I can say, i've been spending quite a bit of time in the 04 X5 4.4i over the xmas break, and i have to say that the thing is AWESOME. A lot better than the old 4.4i. Definately noticebale is the speed, this thing hauls ass for a heavy SUV, and handles amazing as well. The thing is loud as hell from the outside too and looks good too with the angel eyes
I love this thing and can't wait till the 4.8 comes out!