I'm pretty much the same "IRL" so far as I can tell. The only thing that differs when I communicate online is that I can seem pretty cold and boring, but TA has the convenient emoticons that help work against that.

Sometimes people are unconsciously different in temperament online versus in person, which you can't really fault them for. But when someone purposely acts different online than in person because it allows them to talk or act in ways that they wouldn't normally, that just pisses me off. It means they're not sure of who they are.