The X5 with the V8 has nice acceleration and a throaty growl. The ride is noticeably harsher than our MB GL450 and neither really exhibits excessive body roll. On worn highways I often try to drive to the side to get a smoother ride. I really regret getting the side aluminum running boards, they make it much more difficult to get in and out. While many reviews say the iDrive is easy to learn, I sure wish BMW would add more dedicated buttons. The GL450 is much easier to use to access the map, radio, etc.
Great V8 engine, 20 way power (and ventilated) seats, bluetooth, ability to change fan speed and yet still keep "auto" climate setting.
At startup, the backup camera takes way too long to come on. Improve the iDrive. Make the ride less choppy.