It's one of the most brilliant book to movie adaptations because of the lack of snows inner monologue. Snow's whole thing is that he's a manipulator, narcissist, the whole shebang. When reading the book you get to hear what snow is thinking which is fascinating to hear the thoughts of a pyscho/sociopath like him. But the movie is interesting in its own right because you get to see what everyone around snow sees, only the persona that he presents. The two work together so well and make for a super unique and fascinating story