If you haven’t seen Wil Dubois’ blog entry on this yet, I recommend that you read it. Wil, a T1 diabetic, is a doctor in New Mexico. He has been wearing and writing about CGMs for many years.
His December 3 and 8 entries review the Dexcom 7+. He is fun to read and knows his subject.
I agree with some of the comments already posted. I usually see a 15-20 minute lag when going up but a faster response going down. The trend and rate of change info is invaluable. If I see double down arrows (dropping at > 3mg/dl/minute) and I’m still at 120 or 100, it’s got my attention and I’m pricking my finger. Time to get the carbs ready!
The CGM has allowed me to safely lower my A1c from 7.2 to 6.5 in just 60 days. My next A1c is scheduled for the end of this month and if I can believe the data collected by my Dex (I use a computer to download and track my BG data.) then I should test at closer to 6%. My goal is now 5.5%.