no perceivable handling difference but I didn't exactly race it through corners before & after. Used 15mm front and 20mm rear as per recommendation from another member here. They are perfectly even with the flares.

http://www.flickr.com/photos/9165028@N02/3928053386/ It looks pretty bad-ass coming down the street if I may say so.

__________________
'08 X5 3.0si - Alpine White / Saddle Brown interior
Specs: Sport Pkg, Premium Pkg, Tech Pkg, Comfort Access, Aero Kit, Style 433 staggered 20s on Conti DWS
Mods: Carbon 35 tint, LED angel eyes, GP Thunder 7500k fogs, H&R 20mm/25mm spacers, clear reflectors, gunsmoke-tinted taillights
Coded: Digital speedo, windows/sunroof/tailgate close via keyfob

X5 pics at Flickr