I must confess, I find 60fps one of the most overrated and misunderstood features in gaming. I'd take a sold 30fps over a flaky 60fps any day of the week, especially in racing games. A brief moment of slowdown in a racing game is a killer.
I remember GT5P boasting 60fps, until the first time the screen was full of cars and scenery and they might as well have boasted 20fps instead. I guess we're still a long way off that 1080p @ 120fps we were promised
I've certainly never noticed any issues playing Grid, DiRT2, PGR, Forza etc... at 30fps. I guess when you're doing 100+, fps is neither here nor there.
And I never seem to hear the end of the "games at 60fps are faster" argument. Even when I have posted demo projects which show things running at the exact same speed at both 30fps and 60fps, gamers still argue the fact, accusing my demos of being false.