I have an 07 X3, that felt anemic in terms of acceleration, when I first got it.
Resetting the tranny, so that it could learn my habits made all the difference in the world. Since the learning mode lasts for 1000 miles. My guess is, the first time the tranny was "trained" the SUV was probably being broken in, where people have a tendency to drive very light.
A tranny reset, to tune-in the shift pattern and a refresh of the engine's spark plugs and pre-cat O2-senors, to bring back the engine's max torque, really changed my perspective on the X3... big time.
For you guys I'm guessing your mileage is too low to truly warrant a spark plug/sensor tune up. However, if you haven't reset the tranny, post-breakin period... you'll probably be presently surprised if you do.
'11 X3 xDrive35i -- Coded
'07 X3 3.0si -- Coded & Traded
'91 e30 325i -- Sold