When I watch adaptations like this I often wonder if the director actually read the book. Cinematically it's an okay movie, but the deviations change the entire narrative.
If you haven't read the book you'll love it, if you have you'll hate it.
Paul becomes the universe's super being capable of seeing the future and the past not some tormented adolescent incapable of making a decision.
I could go on but it would just emphasize the fact that a movie adaptation is never as good as your imagination.