I don't like Willis' style of running the ball, or rather his hesitation before picking a hole. It seems he used to run pretty well, like in 2005, but in 2006, he seemed to dance too much.
In his personal life, he seems like a bit of an airhead, but I could live with that if he played football well.
He just does not seem to care very much about the game, IMO, so it's his game-time attitude that bugs me.
If the Bills could get a 3rd round pick for him, I would trade him. He is not a franchise back IMO.