There is no real way to determine if the X3 has the transmission issue until you drive it. Take a good test drive, Those with the problem say that places where the gearbox acts up are:

1. When making a turn at 15-25mph and accelerating (i.e out of a corner), the gearbox hunts for gears and does not accelerate properly.

2. When accelerating moderately from 40mph, the transmission hunts for gears and does not accelerate.

3. Downshifts when braking to a stop are unusually severe.

I haven't experienced any of these. I had a '08 X3 loaner, brand new, that was a 11/07 build and it exhibited no unusual problems. Sure, its not as responsive as my '04, but that's the way the new gearbox works. The torque converter is permanently locked right after take-off for a more direct feel and lower fuel consumption. The latest software patch was release in 10/07, and apparently '08 X3s built after 11/07 do not have issues.