Comparing CGMs - What are the differences?

So I've been searching the various threads looking for comparisons and feel like which I know which CGM seems to get the highest reviews. But if you have used or tried more than one of the different CGMs (Dexcom, Medtronic, or Freestyle or other?) and can actually compare them, I would really appreciate your answers to these questions/comparisons. (Or if you've done/seen something similar elsewhere just send me a link to a thread/blog/site.) 

Which ones have you tried?  (Dexcom Seven Plus, Medtronic Guardian/Paradigm, Abbott FreeStyle Navigator)

1) Differences in sensors (Please compare)

a) Ease of insertion

b) Wearability (how well does it stick, etc.)

c) How long does it last?

d) Comfort

e) Accuracy of readings, trending?Accuracydue to age of sensor (either a brand new or as it gets older?)

2) Differences between receivers?

a) Ease of use (viewing data, input calibration points, etc.)

b) Level of detail available (does it show trending up/down, history, etc.)

c) General signal quality (missed data points, etc.)

3) Differences between software?

a) How often do you use the software?

b) Ease of use?

c) Level of detail?

d) Overall quality of presentation?