There is already a thread on this.
Anyway, I watched this film not really expecting anything, and it started off a really visceral and powerful film, but as soon as Michael escaped from prison after his sister, it just turned into a routine slasher film (not that I have anything against them, I love slasher movies). To go from being so depressing yet powerful, to a slasher movie means it isn't really a good movie. Plus, the running time is just a bit too long.
However, Malcolm McDowell was great. The best performance of his since A Clockwork Orange. His mere prescence redeems quite a large part of the film.