All of the enthusiast car mags seem to hate the X6. I was about to spring for a 2010 X5 diesel, and then saw my first X6. Wow. Went with the 5.0 twin turbo. Being built right now, and should be delivered at end of this month. Very different vehicle than the X5 in many ways, and drives unlike anything this large should. I think that it is a work of art in motion, but many people think it's ugly. Certainly not very practical for a family (we have no kids but two cats who probably won't be riding on the two rear seats), but can haul a lot of stuff with rear seats folded down.

About your question of how many are being built; I was told by the sales manager at SunMotorCars BMW in Mechanicsburg, PA that only one out of approximately 10 or 12 X vehicles produced in South Carolina plant are X6's. Both X5 and X6 (in all varieties for worldwide distribution) are made on the same production line. I think that BMW has figured that the X6 would be a limited production "niche" vehicle, which has seemed to be an accurate prediction so far. All I can say, is once you drive an X6, the X5 feels much heavier and less agile. Certainly not for everyone, but a very exciting driving machine.