This is based on the book only in the most tangential way. They turned the book into a joke. They may never be able get it right. In Hollywood they focus too much on the violence. It could be made as a foreign film. It needs to be done straight and without a soundtrack, and not as a horror film.
For all its purported shock value circa 2000, both the sex and violence and the satire are toned down quite a bit compared to the book (which makes it less exploitative, which is good, and less disturbing, which is not as good) - though thankfully the tone mostly makes it intact.
This is one of the most dynamic, virtuosic, hilarious, unforgettable screen performances ever. The film itself functions equally well on the levels of character study, social satire, period piece, absurdist slasher farce, and mindfuck psychodrama. Next to the irrepressible Christian Bale, the film's greatest asset might be the female eye behind the camera, lending this study of male vanity and insecurity real bite.