I was reading this review of his comedy and I pretty much agree it's accurate. Here's the first paragraph of it.
'Dane Cook is awful. He's worse than not funny, he's anti-funny. If I had to picture the personality that would typify every stereotype of a yuppie in California combined with a yuppie in Soho it would be Cook. His
whole act appears to be an attempt to set up a joke that never happens. If you had to ask me what the best joke of his act was I couldn't even tell you. It all seemed to revolve around the social behaviors of superficial people and how they react to each others superficiality. It's like he's giving a lesson on how to be the perfect douchbag and his audience is taking a seminar with him to learn from the master.'