I thought it was well written, there aren't many movies that I can think of where it's mostly just two characters in a room by themselves talking. Ellen Page was fairly impressive. The Little Red Ridinghood allegory at the end seemed a little too cutesy for its' own good, but I liked the premise of a psycho turning the tables on a stalker.
Do you ever check out the message boards at IMDB?
The discussions are usually kind of immature and sometimes trite, but once in a while you find some interesting and thought-provoking comments (not actually the case with this one).
There a lot of folks who had some pretty rude things to say about the movie. But I think it's a bunch of male chauvinist jive, guys just have a problem with it when a female takes care of business like that.
ur not alone on that ocd thing.