One thought throughout the GSP fight that kept coming back to me is how much he sticks to a game plan, and how patient he is. GSP fights like a machine. There are very few (obviously some, like how he consistently gets too high when he takes someone's back) holes in his game, but he has pretty much perfected the take down and avoids taking any damage.
I just think perhaps he has grown too cautious. It is almost like there is so much technically going on in his head + so much "game plan", that he doesn't seem willing to just let it go and get vicious. Forget the armbar and kimura, I think he could have pummelled Hardy into oblivion, or a darce choke, or the arm triangle looked to be there all night... It seemed almost as though that wasn't part of his game plan, so he didn't try.
Basically, he has become one of the most perfect defensive fighters in the game. I can't really blame him. After all, the 2 goals in any fight are to win and to avoid damage. He succeeds. His offense seems to have suffered though.
I just think perhaps, a little more raw aggression, like he had earlier in his career, would be more entertaining... and maybe more convincing for some people of just how good he is.