I can't say much for the movie on its own, as I prepared for seeing it (and seeing Katja... hmmm) by reading the book first.
The book on its own is done quite well; the novel of an adolescence, his dual life, his frustration with love and the way he tries to struggle through life isn't all that bad. When watching the movie, though, it became apparent to me that almost all of those motives/themes are lost.
The casting is done well - both main characters (Katja Schuurman - I only know her acting from a Dutch theatre-play, and Egbert Jan Weeber, whom I only know from "Van God Los") are especially fit for the role they play.
The movie by itself (without knowledge of the book) must be confusing to most or seem like scenes loosely put together. It might have been maimed in the editing, or perhaps the screenwriter has a different view on how to construct a movie then I do. They tried hard to show the all-consuming character of the relationship by putting in a few very steamy sex-scenes, but ended up doing what just every other dutch movie does: profiling itself just because of those sex-scenes (which is what other comments point out quite clearly). Which is a shame, since the original story behind it is quite a bit more. Well, not Tolstoi, but OK :-)
