I've been considering it, but so many other games have come out at the same time like MW3, BF3, Saints row 3 etc.
I like forza 3, I played ages, being able to practically paint your own designs for a car was awesome. I might buy forza 4 when it comes out a bit cheaper and I'm sick of the three games mentoned previously.
It's not a bad game, but I still believe it doesn't feel like a simulator. Feels like NFS Shift a bit.
And no endurance races in career? I will say the customizations are pretty sweet though. If you are into racing games and have a 360 I'd say buy it.
I just got it and i know nothing about actual cars but i find it pretty fun, although the online drifting modes get annoying when the only thing anyone does is ram into you