I've been in exactly the same situation but I purchased an M3 instead. Although I've since sold the M3, I don't miss it from the practicality aspect which the X5 wins hands down. I got it out of my system although it cost me close to £3k in depreciation over a 5 month period. If I had the choice, I would have just gone for the X5.

I do miss the raw power of my e46 M3, the X5 does not dissapoint and thats with a 3.0d Sport!!