The years of bashing Ben Affleck either for his lamer roles or his private life have to be over. For this gangster vs. cops thriller he does not only deliver an almost flawless directing job but also the best acting performance of his career.
His supporting cast is just as excellent: Jeremy Renner ("The hurt locker" ) manages to squeeze hints of humanity into his role as brute and unpredictable partner in crime. The FBI characters (Jon Hamm of "Mad Men" and "Lost's"-Man in Black Titus Welliver) are not quite as deeply developed as the bankrobbers' and their investigations remain a tad superficial, but their outstanding acting more than makes up for that.
The movie's biggest asset is how it manages to make you care for the crooks almost to the degree of you wanting them to get away with it. Especially Affleck's growing romance with the victim of the first heist (excellent: Rebecca Hall) is really well done and delivers a few really deep and touching scenes. Of course this wouldn't be a gangster thriller if the amount of fired lead wouldn't rise significantly towards the end.
The showdown and final heist turns out so exciting and enthralling that you actually feel like fleeing the scene a couple of times. The fact that the solution does not entirely follow the conventions of the genre is just another big plus.

Easily the best film of this genre since "Heat" and certainly better than "The departed". Highly recommended.

9 out of 10 nun masks.