One of my friend recommended this movie to me, I saw a lot of negative reviews and ended up watching the movie because of Adrien Brody and Adrien Brody only.
(No Spoilers) The story line is simple and it's "Redemption". Well, you know the world, it acts quite opposite to what you actually wanted, if you want a peaceful life, world will throw you the hard one and vice verse.
Story runs little slow and the main thing is that we need to understand/assume few things from the glimpses of Clean's (Brody) past. Director of this movie is very precise and he did a good job letting us know what we supposed to know.
I learned a life lesson from this movie which contains the spoiler and I won't reveal it and hoping you'll learn it too.
Bottomline: Give it a try, you wont be disappointed, I mean you won't be disappointed completely.