Forza was fun, but the AI is retarded, and the grip never feels 'correct'. Also, thumb sticks.
FYI iRacing is 3 for 1 right now. 12 bucks for three months. The Williams FW31 is simulated with data and real physics. F1 2011 is too easy. Nobody should be able to do a semi hot lap within a few 10ths of the real guys so quickly like I could. Its just so unrealistic, but not everyone wants realism. People like us in an F1 car would just spin it and look generally stupid.
The challenge is greater, and the rewards come in a little slower but it is far more worth it when you start getting on the pace.
Also, there are dedicated stewards that review incidents, and give out punishment. I had someone try to run me off the road for what was viewed as my fault by him, but I actually did nothing wrong. I supplied evidence and the guy was reprimanded.
Just do it, if you have a wheel you will have zero regrets. If you only have an xbox controller, don't bother