I voted physics, because although there are issues that need fixing (ability to do stoppies etc, probably down to slightly exaggerated weight transfer), some people are shocked that you can't go flat out through every corner because they've been playing NFS or some other arcadey car game and expect it to be the benchmark for realistic physics. I think GT6 has brought along with it some very casual gamers who don't really care for cars that much... PD's attempt at making the game more accessible has worked against it in both ways - seasoned players think the AI is too easy, and new casual players hate the more realistic physic because they are just not used to it.