It pretty much felt like "the movie that started the series" from the 80s.

A lot of the stuff is basically the Gunslinger telling his story or thinking about the past. Sure it gives a nice explanation about the current status of the characters, but it also drains the amount of "current status".

Also, some descriptions felt hard to follow. Sure it's easy to explain how a train station looks like and what's in it, but a cave... Good luck following what's happening there.