This film was absolutely fantastic to see. It has successfully created a backdrop that captures the magic of Harry's world and has simplified many things. (As it must to fit into the imposing time limit of the film.) However, the dazzling effects and beautiful sets cannot override a general understanding of the original book series on which the films are based. Severus Snape is one of the most complex and pivotal characters in the books, and this film rearranged his character and turned the Head of Slytherin into a Gryffindor.
I'm curious to see how it all works out in the next film.