I was using way more insulin on the MM pump than on the Animas. No clue why that is, and I'm not saying the same will be true for you, because I realize it's weird...but it's true for me. I was using about 75u/day with MM. Went to Animas with no changes to food or activity and instantly was having lows and needed to decrease to about 60u/day. I thought maybe it had something to do with the delivery rate (much faster on Animas) but no one's ever been able to confirm or deny that for me. I now use even less, but that has to do with dietary change.
So again..........not saying it will happen to you, but just saying it did for me. And.....has this happened to anyone else??? Because now I feel weird :)