I'm not too big a fan of his music, nothing really special about it to me.
He does have an excellent way of selling his music by using the shock-effect. Nice marketing trick.
I saw him live once(at a festival, I didn't pay to see them exclusively), and I have to say I was surprised. He's one hell of a performer, not only putting up a show that doesn't bore you after 2 minutes, but also doing a good job at singing.(I'll leave it up to you to decide if his vocals can be described as singing)