UPDATE:
I still haven't driven my car since it's been in the shop but according to the techs, the software update changed the tach/engine problem. Instead of the tach jumping up (and then back down) when you begin acceleration, the tach now lowers for a second (and then comes back up) when you accelerate. Either way, the engine hesitation is still there. The techs and the 2 field service engineers do not believe this is related to the clutch. They are currently working on the wiring or main computer.
One thing that is confusing the whole issue is that there are so many people involved in the diagnosis that I get updates from a different person each time. They have still failed to provide me with any sort of paperwork stating exactly what has been done to the car, what stock parts have been swapped out with other stock 135i's on the lot, etc.
I'm sure I will have some interesting updates soon.....
