I can see why some might not like Dan's style, or need time to adjust to it. I get the impression that Dan says what comes to mind, rather than reading from a script. He's verbose, talks fast, and adds a lot of side stories. Maybe that's why I like him. Simon Winchester, who reads his own audiobooks, is similar. My favorite teachers/professors were the same way.
"Before I can tell you this story, I have to explain three other things first, and I'll probably go off on a couple tangents along the way..."