Like BMWMAN said, choice is easy X5M>5.0>35, it is all the matter of how much money you want to spend. When I was looking to get an X5, it started with
4.8. But that was in September and I knew the new 5.0 was coming. Plus after optioning the 4.8, it ended up 75K. I managed to justify 15K more for M, the price differential is not as significant as you think.