I disagree with BMW007. Get the X5 35d.

I own both a 2011 F350 6.7 PSD King Ranch and a 2011 X5 35d. You can't have too much of a good thing and the X5 35d has far better linear accleration w/o any of the noisy reving drama of the gasser version. And while my truck puts out 800 ft/lbs of stump pulling power, the X5 6 speed is my rocket ride of choice when not towing my heavier toys. BTW, the X5 35d tows my 5500 boat and trailer with no drama as well.

Go 35d! You will not regret it.