Correct me if I'm wrong but isn't all the top raiding guild on PvP server? And isn't it just those guilds that progress the fastest? I would think it would be logical to assume that people that prefer PvP sever are more competative minded people, and wouldn't that spike a greater willingness to progress faster?

I personally think that the diffeculty of raiding doesn't have anything to do with which server you are but rather the skill of the raid.

And please as multiboxers you should all be ashamed about talking about someone getting an adventage for transfering to a PvP server. If there ever was someone with an advantage on any server it would be everyone on this forum.