He is without a doubt the most naturally gifted centre in Super League - and I'd say has all the attributes to be one of, if not the best centre in the world. He's big, strong, fast, good hands, runs good lines, great motor and is a brilliant defender.
His problem is that he doesn't impose himself on either the game or his opposite number - or certainly not often enough. He should be demanding the ball, and often. I think a big part of his issue is actually his quiet and unassuming personality - he needs a bit of 'jeremy hunt' in him. If he had a Justin Hodges type attitude, where he wanted to destroy and humiliate the opposition at every opportunity, you'd see a much more consistent performer.