Yes, as the two previous guys mentioned, the AI is a massive improvement here. I've only had chance to do the first two full weekend races on career mode, and I agree, you do have to make full use of the practice sessions in the hardest modes.
This game is a real simulation, Codemasters are far more advanced with real physics than EA (Need for Speed) or any competitors and handles like the previous F1 2010 game or Grid (both classic games) BUT F1 2011 does take it to the next level in terms of the extra touches.
This game is for enthusiasts rather than gamers who like Need for Speed / Outrun / Burnout etc etc
Looking forward to racing online against 15 other gamers!
"That's what I'm talking about!!!"