That 'over' draft issue is common with everyone that uses auto-checking-withdrawal.

Since I'm a male, I don't get to workout at curves, but I have a friend that owns one and from what I've seen, my opinion is that it's biggest drawback is that most, if not all women that use it like they should, will outgrow it pretty quickly. I suppose it would always be a good place to go burn some calories, but real muscle tone and strength will decline at some point.