Pretty good. A few minor tweaks would make it even better.

Rating: 7/10 (21 September 2016)

** This contains spoilers! **
Edward Norton is frighteningly believable as a skinhead in this movie. In general, I thought the acting was good. This movie is kind of like The Shawshank Redemption -- except with less hair.
It's well shot and edited. The pacing slows down a bit for the second half (which is pretty typical of most film plot arcs). However, it delivers the goods.
One issue I had with this movie is that it borders on being a bit too soft in certain areas. For example, Derek's character changes a bit too quickly. I understand that there's limited time in a single film to explore a person's change of heart. To that end, having him not cry after he gets prison-raped would have been a better way to go. A guy that's actually that pis*ed off and aggressive would not cry in a situation like that. He'd be upset -- no doubt, but he wouldn't break like that. It would be more believable if he reacted like someone who was injured in a fight and genuinely insulted and even embarrassed (but not willing to show it). More stoic is what I'm thinking here. The crying should have only happened once in the film and that's at the end when his brother dies. That would give the death scene at the end even more weight.
At the end of the day, Derek cares about his family and that's the secret to cracking his armor.