Nice review!! About the iDrive comment, to be completely honest, the iDrive in the 5 and the 3 are really easy to use and I guess it would be the same for the X5 as well.
BUT, I've used the iDrive in the pre-facelift 7 and facelift 7 and I must say it is absolutely crap. Even after using the iDrive in the M5 for a very long time I really couldn't understand the way the iDrive in the 7 worked. It was incredibly frustrating to me. The iDrive in the 5 however was absolutely easy to use other than the really sluggish interface.

P.S. I'm someone who is very computer friendly and not a technologically dumb person.