Seen this twice. Didn't love it, but it wasn't bad. I can see why it might be that kind of movie people really get into, the characters were... interesting.
This movie came up in our flat once, a flat of six guys, and no-one was keen on it. One of my flatmates made the claim that "it's a movie Americans love and everyone else hates". Which isn't true, of course, but to my knowledge, I'm yet to ever hear anyone mention this in one of those film-pimping conversations you have occasionally, and it seems insanely widely appreciated in America.