I have both a set of 20's and a set of 19's. I love the look of the 20" wheels on my X5 (Sport Activity option). I haven't had the uneaven wear or other issues I've read about here. Note that the 20's are staggered and therefore can't be rotated and will likely wear faster - I have 12K mi and still plenty of tread left. They also have summer rubber - so if you live anywhere that gets below freezing you will want a set of 18" or 19" with winter or all-season tires for that time of year.
I've got my 19" tires on now with the stock all-season RF's (picked up a complete set of take-offs). There is no question that the 19's smooth out the ride a bit, and would love to try non-RF tires sometime. But having said that, the ride on the 20's doesn't bother me.
2011 X5 xDrive35d Black Sapphire/Oyster
Packages: Premium; Technology; Sport Activity Activity; Convienence; Rear Climate
Last edited by Brother_Bluto; 12-03-2012 at 12:20 PM.