I have a G25 the steering is so vague and FF effects are non existant, nice graphics though, shame is dont use my triple crossfire x.
get around 35 fps with CC on 4x AA temperal max everything else and maxed in game, but it is smooth as butter, so not looking to much into it.
i would advise you to check out this official GRID forums tech thread regarding FF problems http://community.codemasters.com/forum/showthread.php?t=279788 as i have a G25 and can assure you the force feedback is spot on in GRID and adds depth to the experience