There were a couple of scenes that weren't in the show, and thus new to me, that I loved (e.g. the Four Horsemen standing around the signpost, and I liked the trivia scene better in the book than in the show + the Them had some amazing dialogue and inner narration that wasn't all included), but there were also some racist or homophobic lines/slurs that I'm really glad were cut out, including a joke about burning gay people that REALLY took me out of the story and I still haven't really processed that it was like, actually there and I didn't dream it.

In short: 80% of this book was almost exactly the same as the show (= amazing), but for the remaining 20, I think I preferred the show.