In my previous posts, I didnt mean to come off sounding like an ass, but I did.
But the X5's tires are very similiar to a cars, and if a wagon is available with AWD, it would have the almost the same traction as the X5. And the X5 4.4 gets 12% or so worse mileage, which is significant (although not so much at this price)
And if you dont need off-roading or towing (which the X5 is not suited to anyway, it is a unibody), get a car or AWD wagon. Thats my stance and I'm sticking to it