"I Would Go, But... My Character Wouldn't Do THAT"

It's official, roleplaying gets in the way of powergaming. Over at PlayOn, they've determined (with science!) that RP server characters level less than on PvE servers, and definitely less than PvP server characters. I'd presume this is generically because they're standing around talking. And this made complete sense to me, because it's hard to pick up a group to just go do something when there's so much potential drama attached. Oh wait, this character can't go there, let me go get my alt... wait, he needs to gear up. You all know what I'm saying. Suddenly, it's an hour later and you're still in the tavern.