This movie had some interesting ideas and twists. I thought everyone in the film was messed up and I wouldn't have minded if any of the suspects were "the one." Each suspect had his own perverted/sexist ideas about women so I honestly didn't know which creep did the murders.
A sidenote: There is a striptease scene in the movie that I have seen in another horror movie. This exact striptease footage is from another movie, but I don't remember which one.
All in all, it is an interesting film and I think it pushes some boundaries moreso than most other sex-maniac focused horror movies. There are parts of this movie (basically all the parts that took place in that little room with all the pictures) that were actually disturbing to me as a woman. Nearly all other sex maniac horror movies do not step over this line of discomfort.
I say a movie that can cause discomfort like this is a successful movie in some ways. I give it a 5/10.