I agree very much with Jason that the one short-coming of the film was that because of the bizarre final hours of Norton's character, we as the audience were only engaged in his story, and we did not fully internalize his struggle.
It's a very disturbing idea to think about going to prison for a long time. I would guess that most parents have disturbing thoughts all the time wondering what their child's life would be like without them (if they died or something), but going to prison is sort a whole new ball of wax. In prison, you get to experience the suffering of those who count on you and whom you have let down. You get to deal with the worry that your spouse is going to divorce you and move on, and you get to know all of the events in your children's lives that you are missing. You get to worry about being sodomized repeatedly because you are an easy target, and you get to worry that there's nobody out there to protect your family.
As for the film, it was a bit of a contrived story, obviously, but I thought it was well done. Jason, I think that maybe the disturbing scene that Dave Chen was referring to was the scene where Norton's character asks his friend to beat the living hell out of him. If so, I agree. It was beautifully disturbing, and quite powerful. Although I must say, don't have your friend punch you in the head while your head is already on the pavement. Bad idea.
-comments by Andy