I got the F sport springs which will basically make you look like a stock 250 cept maybe give or take 1/4" lower which is nice... unless you drift towards the even lower look which some times I do, and I regretted my spring choice. But in the end I feel its pretty good, a compromise between looking good and not having to worry too much about the road condition for a daily driver.
Height difference is listed in Lexus IS brochure at 0.6".
I saw my first IS250 AWD in person a few weeks ago (they are pretty rare here in AWD form) and I could easily see the difference in fender gap.
__________________
S.
2007 IS350 (sport pkg) smoky granite mica/gray
2008 C300 Sport mars red/black
2002 KJ Sport (3.7L 4wd) white/gray
Enjoying Lexus ownership and valuable interaction with owners on CL Lexus Model Forums, and occasionally amused by time-wasting CHIT CHAT General Forum too.