I recently started on G6, after several years on G4/G5. I am VERY disappointed in this product. First, it ALWAyS reads low at the start, and by low I mean ridiculous. Normally, 3-4 hours in, it is reading about 40-45 when my blood sugar is 90-130. I’m on my 5th sensor, and that behavior has been constant. I’ve started now trying to reduce the problem by inserting the new sensor 6-7 hours in advance, so that when I actually switch, it’s only bonkers for ~12 hours instead of ~18. I can’t imagine how they think this thing is good enough for controlling a pump! The even more annoying part is that (despite advertising to the contrary) IT WILL NOT ACCEPT A CALIBRATION during this period, because it will only accept the calibration if it agrees with the reading within some limit. And, even worse, if you try to do a calibration, it stops reading at all until you submit a calibration you agree with. I made the mistake of trying to calibrate it with my first sensor, and wound up attempting 9 calibrations over 12 hours before it finally accepted one and started giving me readings. And the ridiculously complex mechanism for acknowledging an alert is just an abysmal design. On the G5, I could hear the alert, push the button, and that was it. On this thing, I have to open it up, perform 4 actions, and, if I’m not very fast about it, it turns off and I have to start over. The click on the OK icon appears to be especially unreliable. I have to hit it 3-6 times before it accepts the OK. Almost never works the first one or two times. It can take 1-2 full minutes of fiddling to get the alert canceled. There are many social/work situations where that will be very objectionable. Why they didn’t give you an option for use of the button is beyond me (maybe a double click?). The G5 was well designed. This thing is garbage.