Thanks for digging up this old thread! I think the increments should be a pretty big concern to the medical industry? I know you do a much better job keeping track of data than I do Jen, but the fact that you've noticed the difference with smaller increments seems like it would be easy to fix (pumps or diluants...) and it would help people achieve a different degree of precision than they or their doctors are used to?
I guess I am sort of cocky about it but if my basal is pounding me down to 65 every day, I can turn it down, just a smidgen (I think it's .025 U/ hour...at least w/ the Medtronic -23 serie pumps...) and it seems to nudge it like 20-30 points in the right direction so I can be pretty much where I want to be. The same sort of goes for bolus ratios although I think that I sort of run my ratios a bit "hot", and eat a bit extra to make up for the "shortfall" rather than thinking about it a lot.
The Medtronic uses 1% increments for temporary basals so you can do very precise numbers, use lucky numbers (7, 13, etc.) for fun, etc.
I understand Shoshana's point about gastroparesis being very difficult to control things but it seems like, in general, with "normal" diabetes, a lot of people find it difficult to manage and think they are making mistakes when the mistake is that doctors don't do what it takes to manage insulin dosing more precisely. Since the doctors have abandoned precision, obtaining a scientifically precise result or hitting targets becomes more difficult. Pens are very popular but 1/2U increments may not be matched perfectly to everyone. Insulin is strong stuff and if you're a little bit off, it's either eat more or run high.