This game is almost perfect. I miss only more cars and brand diversity (not only 1-2 or 2-3 Jaguar Mercedes because Forza 3 is simply the forerunner) and some more tuning options, even if they are also here already really good.
The driving behavior and FFB I find very realistic (Logitech Driving Force GT) and yet not too extreme, so that it can play even inexperienced and have fun with it, the tracks are realistic and beautifully presented and the rest is very consistent.
I just think that you have the "career" a little too fast by, each cup has perhaps ~ 8-10 race, and that is really not much, and the cups, there is then relatively few categories that do not even have to play through it to proceed to the next as sometimes reach 1-2 race, I have already, some cups completely skip, here you have to live with that, there is no motivation that you have to make yourself completely. Not end of the world, yet somehow something bad could have been much better with a little work.
Nevertheless, 5 stars for the game, the reasoning is quite simple:
Shift 2 is the only PC game that at least partially rankommt Forza 3/4. It does not do everything perfect, but many almost perfect, and anything like I have after much trial and error in the racing category (Grid, Dirt, NFS, F1 etc.) is not found.
So are not the 5 stars for a perfect racing game, but in my opinion the best racing game that you can get currently for PC.