I don't have a problem with the concept of ASS and actually I think it's a pretty good idea.
The problem I have is in the implementation of it in the F30. It can't be good for the engine, mounts, and drive train to shudder as violently as it does when stopping and restarting. There is no way to tell how much extra wear/damage this is causing that will shorten the life of these components compared to the savings in fuel/emissions.
First, if the stop/restart operation was smooth (like it is in most other cars with ASS), then I'd use it all the time. The F30 does sometimes stop/restart smoothly, but only about 30% of the time.
Second, having the engine stall on ASS restart is not acceptable. Not even once. That scared the hell out of me as I had to scramble to get the car restarted and back into gear to clear the intersection.
No amount of fuel/emissions savings is going to convince me to use a system that makes me dread coming to a stop wondering if the engine will shake and lurch or might not restart properly.