670G or wait for 780g (currently on TSlimX2)

I was a long time Medtronic 530G user. The warranty ran out so I began using the TSlim X2 in January. I feel I have given the X2 a good run, but I am considering switching to the 670G or even waiting it out till end of 2020 for the 780G which is supposed to have Bluetooth for iPhone. I am looking for honest opinions from people who like one or the other and the reasons why. Don’t get me wrong, I LOVE my dexcom G6 and will greatly miss it and the iPhone capabilities if I switch back to Medtronic, but I just can’t seem to make myself use the TSlim. I end up take too many pump vacations since I can’t get past things like charging the pump, site change time, the tubing connections, the multiple customer service companies I have to deal with to get the various supplies, the inability to override bolus suggestions, and the very loud Suspend alarm. Sometimes I have to suspend due to knowing my body better than the pump at times. With Medtronic it was very quiet and discreet beep, when I would suspend the pump, but TSlim alarms after 15 minutes. I really want to like the TSlim because I love the Dexcom, but the pump is just not working for me in the way I had hoped. I know the Medtronic sensor isn’t the best, but thinking if I deal with that for a little while, Medtronic will inevitably improve on it. Thanks everyone for your thoughts ahead of time. Is there anyone out there like me that tried the TSlim and wants to go back to Medtronic?

I have the 670g, it’s my first pump. I love it and I hate it. Literally as I am typing this sentence, it is vibrating in my pocket, which brings up the first thing I hate about it. If I ignore it, it will continue to beep and vibrate every 30 seconds. After 10 minutes, it will start going off in a horribly obnoxious, the world is ending, alarm until you acknowledge it, or it runs out of batteries in a week or however long that takes. You can pretty inconveniently “Silence all alerts” for up to 24 hours, great for a meeting or something,

okay, I’m about to throw it across the room, I have to acknowledge it now…

I don’t know how the other pumps work, but with the 670g you are basically agreeing to immediately acknowledge every insignificant notification the device has or suffer. I wish it had an “I’m not a child” mode where it could give me alerts briefly and then stop, like any alarm clock or phone ever. The only viable solution seems to be pinpointing the location of the internal speaker and taking a core sample with my cordless drill.

The big complaint people have is sensors. Sure, mine fail early, but it’s always because I didn’t tape it right or I damn near ripped it off on something not being careful. Otherwise, my SG is always within a few % of my BG if not spot on.

Automode is fantastic. It is terrible if you try to trick it with fake carbs to get correction boluses, or if your settings aren’t right. Otherwise, it doesn’t want or need your alleged basal rates, and it will figure it out whether you are having a sick day or running a marathon.


First @RosiesAllStars, let me offer you a Warm Welcome to TypeOneNation forum! A place where each of us is able to express our thoughts and opinion about diabetes and living with TypeOne.

For years I used MiniMed/Medtronic pumps, three progressively improved models, and really liked them and appreciated what they did in my diabetes management. I changed to the Tandem t-Slim x2 in January 2019 and really like it. I believe that every one of your “objections” can be managed if you spend a little time exploring the built in features. Alarms and alerts can be silenced by selecting “vibrate”, an infusion set can be kept working for as long as 300 units of insulin will take care of your needs, etc. I do agree that the cartridge fill procedure is ridiculous - why cant it be as simple as the Medtronic. It is possible to purchase supplies directly from Tandem, the hitch sending you to outside [third party] suppliers could be your insurance company - if you use a third party payer.

The real advantage I see with Tandem is the ability to update the pump software to take advantage of improvements without expending $9,000 for a new pump just to take advantage of innovations; also the Basal IQ is tops and I expect Basal Control [in November] will be awesome. Okay, this bit is only my opinion; I do hope that things work out well for you.

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Hi. Thank you for your reply. I’m glad to hear that you can silence for 24 hours, because with the X2, even though I have it on vibrate, the suspend feature does not care and will beep at the 15 minute mark, overriding the vibrate setting, therefore interrupting meetings, etc. I am glad to hear that the Auto feature works once it gets to know your body. That is encouraging. Let’s say you do not use the pump in automode, does the low threshold still function still work? Also, if not in automode, can you override the suggested bolus amount like how you could on the 530g? Thank you.

Thank you for your thoughts.

Yes, In manual mode there is a “Suspend on Low” and “Suspend Before Low” setting for basal delivery. In manual mode, you can use the “Bolus Wizard”, add extra units to the Bolus Wizard’s suggestion, or enter a unit amount to bolus completely manually. In Manual Mode, you can also use your paired Bayer Contour glucose monitor as a remote control to give boluses.

Automode will not allow manual Boluses, it just wants to know your BG and Carb intake.

The “Silence All Alerts” setting will prevent beeping and vibration, in 30 minute increments, for up to 24 hours. It wont silence Battery Failure(pump is on internal battery and shutdown imminent), I imagine it wouldnt silence sensor glucose is less than 50 alert, or tubing blockage. Those go directly to the super loud alarm, but dont happen often.
You can also turn down the volume to vibrate, but some alerts still make noise…

My take is that if one has a high A1c or suffers from lots of lows, the 670g now may be the way to go. If you are currently in fairly good control, I suggest waiting for the 780g.

I was under good control with few lows before the 670g. I went with it hoping to reduce my mental burden, but it doesn’t really help on that front. I have been on the 670g for about a year and a half. The good news is that lows are even more rare (mostly the tricky issue of exercise). If one has sensor or calibration issues, sometimes they can be improved with changing sensor location or inserting the next sensor in advance. The new transmitter has really helped with my calibration woes.

Auto mode’s intelligence has some real limitations. It never learns daily patterns to address things like dawn phenomenon. It is extremely stingy on insulin. Micro boluses almost always stop after boluses or when under 120. It should be able to deliver strong bursts when BS begins to rise, but it doesn’t seem to work out about half the time.

I am subject to dumb boom/bust cycles where auto mode will work great and keep me in range 90-100% with maximum micro boluses as high as 0.150 or 0.175 units when I’m rising. Then the pump decides after about two weeks that I can’t have nice things and will limit the maximum micros to 0.075 or 0.100. I stay high for hours and use all of my will to remain in auto and avoid rage bolusing. Dawn phenomenon is a real problem for me when the pump is stingy. This is even more perplexing since my daily insulin use is very consistent.

I think the 780g will address some of these issues. Calibrations should be better. There should be better, more automatic corrections.

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Thanks for the helpful information. I just saw that there will be a clinical trial for the 780G, so I am hesitant to wait since I feel that may be at least 2 years out to bring to market. If anyone knows of a better release date let me know. My A1C was 8.3! Terrible I know! So disappointed because I was always a solid 7, but this last year has been crazy with trying to manage my control. I meet with the Medtronic rep tomorrow and am pretty sure that I will bite the bullet and make the switch. They said I could trade in my TSlim and pay an upgrade fee. Hopefully Medtronic will have a reasonable upgrade program for people switching from 670 to 780. I feel instead of wasting time waiting for the next best thing, I just need to make the switch. Seems like Medtronic and Tandem schedule new releases every two years give it take, so then I sit with poor control justifying the wait, but I just need to do it. There will never be a perfect time to buy since the tech is moving so quickly. And you know what? Maybe having less tech may be a good thing. The time I spend checking my phone and watch for my Dexcom, adds up to more time than I used when I just had access to the readings on my Medtronic pump. It’s as if I have too much info and end up on a roller coaster. Thanks for listening (reading)!

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Have you tried changing your insulin sensitivity factor for the time period you experience the dawn phenomenon? Just tell it you need more units per mg/dL during this time frame.

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This forum has helped me a lot I was having a bad reaction to insulin aspart since 2016 no Dr could figure it out but I got on here and there it was. It has only been 3 weeks but I feel closer to myself then I have in 20 years. Here is my story with the 670g. I have lots of bads about the 670g like the constant sensor updating, or how it will beep and yell at me in the middle of my sleep and doesn’t stop until I wake up. Or how I have to constantly call in for my sensor failing on the fourth or fifth day. But they send out new ones everytime I call in. But the best thing is it has saved my life. I would of never got my a1c to a 7.1 if it wasn’t for the pump. It is awesome for me because everyday with my diabetes is different I could eat the same meal everyday and I still had extremely highs and then extreme lows. I could get down in the 20s and still be awake. Really scary always made me feel like I was going to die any minute. The 670g is perfect for me for the constant correction it does all day. I get mad at it but then I remember it is saving my life I don’t think I would be here today without it. Personally if I didn’t use my countinues monitoring I would go back to my last pump. I will be switching to 780g as soon as it comes out just for the convince and discrete of being able to use my phone like everyone around me is using. Those looks or question are emotionally draining for me

Edward, I spent months experimenting with lower carb ratios (extremely low at times) overnight/early morning with no noticeable effect. All sources I have seen indicate that the insulin sensitivity setting has no impact on auto mode.

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Bluetooth is not a plus for me.
My iPhone already has enough things draining the battery

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So I’ve been on the 670G for about 3 months or so and I can say that it’s been good and bad as others have said.

This is the first time I’ve been on CGM as I was previously on an Accu-Chek Combo pump which worked great but A1C sat at around 7-7.5%. In total, I would probably spend about 2 mins max per day treating my diabetes. I now spend about 15-20 mins per day treating my diabetes. I suppose this is due to having the “visibility” that a sensor gives and making corrections based on this. My A1C is now 6.5% :sunglasses:

I must say that Medtronic support staff are fantastic- they’ve replaced numerous sensors, a transmitter and even my 670G pump after too many weird alerts during the night. Bottom line here is that they were determined to get the system to work for me.

My findings is that it’s not the type of system where you put it in Automode and forget about it- I find it to be quite the opposite and perhaps this is my own need to control my BG.s. Having said this, I wake up with perfect BG’s every morning which is great!

Some of the issues:

  • The sensor system is terrible - it’s beyond outdated- I wish Medtronic would just buy out Abbot’s Libra System and use this- an all in one sensor that lasts 14 days.
  • The pump is overly stingy when it comes to correction doses. If my BG is high and or rapidly rising, I often exit auto mode and do manual boluses on the pump until my sugars are normal again before going back into Automode.
  • You cannot tell the pump if you’ve had to do a bolus with a syringe/pen. To do this, I disconnect the pump, go into manual mode, enter the manual bolus amount, let it dose and reconnect. I then give myself the same dosage using an insulin pen.
  • The lack of ability to view my BG’s on my phone/PC is annoying but I’m using Nightscout to do this.
  • The temp target for exercise is completely ineffective in my opinion.


  • Lower A1C - this is the key here
  • Great support which are willing to help
  • When it works, it works great.
  • Time in range 83%
  • In Automode most of the time
  • Personally not getting any funny errors/alerts

From my experience, I would recommend getting the pump now - it’s not perfect, it’s never going to be but it’s a really good effort in my opinion.

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Thank you so much for this post. This is really helpful information! It all makes sense.

I ended up getting the 670g. So far so good. I have not switched to auto mode but plan to do that this week. I wanted to get my manual mode basals down pat first. I’m still tweeking them because the doctor ended up resetting all basals to one number for 24 hours since my A1C was so high. She wanted a clean slate to adjust from. So far I am loving this pump over the T-Slim I was using. I do agree with your thoughts on Libre or even Dexcom and the iPhone connections. Maybe I will look into Night Scout. Is that difficult to set up?

I will say I haven’t had any issues with the Medtronic sensor being quirky thus far Cross Fingers! This was a pleasant surprise. It doesn’t feel as secure on the skin as the dexcom though.

Thanks again for your highlights. Please reply with any info on Night scout that may be helpful : )

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Your bolus estimate settings are more important to Auto Mode than basal rate, Auto Mode disregards your programmed basal rates. Carb ratio, insulin sensitivity factor, and active insulin time are the setting that will cause Auto Mode to have errors if not set correctly.

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Muttley Martin, I really wish that your points would be taken to heart by Medtronic so they can address the real issues with 670G. I can’t help but feel that if users like you had been involved during development and testing, these glaring issues could have been avoided. Perhaps, I am naive, but, just don’t get why it’s this way. It’s like the 670G would really be GREAT, if it would just get out of its own way.


Nightscout is a bit tricky to setup but instructions can be found here:


There’s also a Nightscout Facebook group with folk who are super helpful. I contacted Lennart Goedhart who assisted me.

You’ll need an additional Android phone and an OTG cable (available from Amazon). I land up having to lug around an additional phone with me so it is a bit of a pain as I have an iPhone.

NB: Do not mentioned to Medtronic that you are using Nighscout, apparently this can void your warranty :man_shrugging:

Do you know if the basal rates that AutoMode figures out, are they displayed on the Carelink and Tidepool Reports? This would be helpful because then I could adjust the Manual Basal Rates to more closely reflect the AutoMode should I ever switch back to Manual Mode. Thanks for all of your insight.

Hi Dennis.

I see and read a lot of your posts. Thanks for that.
I know you’re on Medicare so you use Dexcom but curious if you were ever on the 670g?

I’m thinking of switching to Tslim x2 with dexcom G6. I’m struggling with The decision though as it requires some loop holes… paying a $1000 for Tandems upgrade program buy the dexcom transmitters out of pocket at Costco dice my medtronic guardian CGM is still in warranty…

All that said I guess I’m just nervous to switch as I’ve been with Medtronic so long.



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Hi Brie, @briew

Thanks for your words of encouragement - I do read all posts on this site ad add my comments when and if I feel I might add something useful.

I have NOT used the 670G - although all my pumps had been MiniMed/Medtronic. I did make the decision to change to Tandem last January.

My thoughts at the time was primarily so I could link my pump to a Dexcom CGM - which I began a year ago today as they were the only continuous monitors approved by Medicare. The second, although also very strong reason, is the ability to upgrade Tandem software as new and improved management tools are released; between replacements required beneficiaries to wait out the entire pump manufacturer’s warranty PLUS an additional year.

Making a change for me was a BIG choice that wasn’t easy. I talked with Tandem and Medtronic people and got a lot of information - the Medtronic trainer was awesome with her help - and read reviews and reports on all pump choices before making the jump. And it turns out that Tandem was able to get me complete payment from United Health; I only paid the $780 DME 20%.


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