As a contender his shtick came across as if he had a massive chip on his shoulder from not getting the respect that he (in most people's opinions) wasn't really due. Now that he's actually won he's more self-assured, and he no longer has to hide his insecurities behind bravado. Instead, he can be self-deprecating. He's more honest, funny, and less whiny.
Also, I do realize that I just created an account and that my first post is in a thread about Bisping; specifically, to psychoanalyze him. I don't know what this says about me as a person, but I'm concerned.