I'm a librarian who loves anime, manga, and reading a wide variety of genres.
This is due in four days. I could probably push really hard and get through it, but I'm not sure I want to. Parts of it are definitely better than the movie, while other parts are...not. It fleshes out a lot of the characters more and makes them more sympathetic, which is nice, except not always necessary.
For example, if the plot stays the same as in the movie, there isn't much of a reason to flesh out Lainie, Strickland's wife, the way this book is doing. At best, it reassures readers that she'll somehow manage to be fine after the events at the end. As far as the attempts to make Strickland more sympathetic go, he's supposed to be one of the book's horrible villains. I don't need him to be more sympathetic.
Zelda is a stronger character here than in the movie, where the only thing that saved her was Octavia Spencer's acting skills. Unfortunately, Elisa is somehow less sympathetic in the book than in the movie. She's the main character so this isn't good.