The Guardian, so far, has worked amazingly for me. I don't think it lags behind the blood sugar because if I eat a piece of white bread I see the number on my monitor go up within five minutes.
I'm paying out of pocket for everything, so I'm trying to stretch out the sensor. The rule of thumb that the minimed rep gave me was that if the ISIG was below 6 when I get the Sensor End message, don't re-use it. So far the ISIGs have stayed well above 6.
My blood sugar in the past six days hasn't been like a nondiabetic's would be, but it's been surprisingly good. I've been over 180 only once, almost all of last night I kept pouring on the insulin. One thing that I hadn't realized was that the Guardian wouldn't give me readings below 40, and in fact there's just empty space on the graph, as though it was a lost sensor. I had had a reading of 60something at work, treated it, and went back to work, leaving the monitor on my work table and helping somebody else at her table. About half an hour later, I went to look at my monitor. It had dropped by ten points per five minutes until it hit 42, and after that I had four readings that only said "below forty". Yuck.
From the Guradian, I have learned the following: my overnight blood sugars go up and down all night long. There is no definite dawn phenomenon, and my blood sugar is not stable. It stays in about a 40 point range. I slept through the hypo alarms and my liver (or something) brought my blood sugar back up before it dropped again.
As I'd suspected, my blood sugar doesn't peak much for meals; when the insulin dose is right it rises no more than forty points. However, the insulin doesn't kick in as early and dramatically as I'd thought; my blood sugar doesn't really dip at the beginning of a meal, or rather, only once so far. Taking insulin after I have already finished a meal makes my blood sugar peak when it wouldn't otherwise.
The effects of excercise tend to happen the most 20-80 minutes after I start.
Keeping my blood sugar nomal in the sense of keeping the fasting numbers in the fasting range and the rest of the numbers in the post prandial range is probably not possible for me, but staying under 200 100% of the time might really be possible. Wow!