To be honest, I felt the '08 X3 loaner I had behaved similarly to my mom's '06 325i. Makes sense, given they use the same gearbox. The shorter gear ratios of the X3 make it rev faster (hence, it's really fast to accelerate) but otherwise I experience similar feel and behaviour.
It's odd that despite having an additional gear, the top gear revs on the highway are the same as my '04 X3. By adding another gear, they basically shortened the first few gears, and gotten rid of the "hole" between top gear and the 2nd-to-top gear that exists on the older 5-speed autos.