After watching the Shift2 vs real life comparison video, I don't see anything wrong with the track in Shift. Ok, a bit more trees, some more trackside objects. But it's all for good. If you want real simulation, go to Germany and race it for real.
As Ian said, they used the real CAD data, so there's not much that could be different between GT5 and Shift2. Some of you only seem to hear what you want to. If a person who has actually been involved in the game development says that it's the same CAD data then I tend to believe him more than some people here. No offense intended to anyone. It's just that I find funny that Ian commented and yet no one seems to pay attention to that. People just keep on blabbing.