William started the Dex on Sept. 26th I think so it has been almost a month. The positives: He likes it a lot. He is very invested in making it work and wants to "prove" to me how great it is - ha ha -since I liked the Nav so much and he didn't. This is the biggest positive for me - that he likes it. He hasn't reacted to the sensor tape and it has stayed stuck for the most part (knock on wood there). Insertion is less fussy than the Nav. Of course no underbandage to cut and all that. Restart is definitely easy Of course the 2 hour start up compared to the Nav's 10 hour start. The calibrations are twice a day more or less, and easy to fit in - unlike the Nav that you really had to get a schedule going for. The cons: The BIGGEST for me is definitely that it can put up those ??? and not give readings but does not alarm you for it. In the end - at night - it makes the Dex worthless - frankly - unless you want to set your alarm to wake up and make sure the darn thing is working. I can't trust it for overnights cause of this. Yes - it far surpasses nothing for overnight but I hate those ??? with no alarm to let you know Of course I liked the range of the Nav - could leave the receiver off. Now he has to wear it and I'm always asking his number. Sometimes he acks it and doesn't tell me it beeped high cause it just vibrates first. The range issue means you need the baby monitor - dislike the baby monitor. Even when it beeps low at night with the baby monitor I don't wake up - it seems to wake up my husband though. So the alarms should be louder for me - with no baby alarm needed. One sensor would not restart - one restarted and was great for 2 weeks - and the 3rd one started having problems about 4 days in and has been off and on the past 3 days (we were traveling). It comes off today. All in all - that is pretty good I think - for the first month. I think if it would just alarm for the ??? after - say - 15 mins of ??? - then I'd be much happier with it. Chances are you aren't going to get the ??? overnight but we've already had one night with a lot of ??? that we didn't know about. 1-2x a month of ??? overnight with no readings and no clue that it wasn't reading is - just ridiculous IMHO. This is such a MAJOR problem with this system - for all the Nav's failings at least the darn thing let you know it wasn't working and could wake you up. I am hoping someone points out some alarm I didn't set that would tell me of the ??? and make me feel like an very happy idiot. I guess I forgot to point out that the accuracy has been pretty good. He definitely tests more - maybe 3-4 tests more a day - than on the Nav. I don't trust it enough to bolus off of it generally but it has been decently accurate - often within the margin of error for the meter. All in all, I am happy with it - I just feel like it is more of a crap shoot than the Nav because of the ???.