I would not pick an RP server for the roleplay. In my experience, the general populations on these servers are more friendly and older. So long as you are careful of half of the RPers. Most of them make the sane and content-driven light/mid rper's look like crap... And then complain when you're not 100% rp walking and 'in character' every minute of your game life. I wanna play the game and be good at it. Not sit in a bar watching bad rp fights while wearing pretty gear and pretending I'm good at it. Sorry, but I want to play the game and make 'real' friends (as real as online friends get, anyways), not make friends with some guys alter-ego.
Not even going to get into the shamefully abundant fetish and erp issues, which are what MANY of the non-rpers see or think when they think 'roleplayer'.