It's mostly Derek though. He so full of it. I've seen reputable mediums in action. None act like him. But if people are entertained by it, then that's cool to.
As of about halfway through Season 6, Derek leaves the show. He is replaced by Gordon Smith, whom I like very much. Yes, I've mentioned the change before, just a few posts up, but just in case ya'll missed it. So if Derek is the reason you stopped watching, feel free to watch again. Gordon works well with David Wells and lacks the over the top drama.
Also, please discuss Derek's new show (which I'm none to fond of) in the thread that already exists for it rather than in here. Discussion of Derek in the Most Haunted thread should remain solely on his part in the Most Haunted Show (live and regular season).