I have yet to test drive a newer (2004+) X5 4.8, but I have heard it is heads above the 2000 X5 4.4 that I currently drive.

There are other SUV/SAV's that peak my interest, mostly the Cayenne TT and the Range Rover Sport (although a lot of people have negative criticism of the drive-ability and creature comforts of the RR). However, there are a lot of things that have kept me from changing to another manufacturer thus far; a good friend of mine is a mechanic at BMW, BMW's are great cars all around and that the price point/resale is still decent on X5's.

So here is the big question, if staying in the BMW family is the best option, will upgrading to a 2004+ X5 4.8 make me that much happier? I know the navigation (although a little dated now), the adjustability in ride height, the added power and all the little things in owning a 'newer' car should help my decision; but is it worth spending 50k on a vehicle that is nearly identical to what I drive now?

Thanks for any opinions, it is much appreciated.

-jason