I saw this at the cinema yesterday. I've not read the book on which it's based, but it certainly has a cleverly plotted and literate screenplay, with great flashes of black humour, and is highly recommended.
I think that what makes the film stand out from the glut of Scandinavian thrillers is the way in which the film reverses our sympathies. We start out loathing the main character, Roger Brown (played by Aksel Hennie), who is an absolute sleazeball - smug, greedy, manipulative and unfaithful to his gorgeous, but much taller, wife (his size seems to give him the sense of insecurity that drives him, and is mentioned at both the beginning and end of the film) - YET we end up rooting for him against his adversary, Clas Greve (played by Nikolaj Coster-Waldau, who also recently appeared in 'Blackthorn' as the young Butch Cassidy). And the reason why the film is able to change the way we feel about Brown is the way in which he is made to atone for his sleazy previous life through a succession of extreme, and often far-fetched, indignities suffered at the hands of Greve. And he is the ultimate survivor, who, once he realises what is going on, is able to put himself one step ahead of his tormentor. We reckon that anyone who can come out the other side of what he is subjected to deserves to come out on top. Yes, he is a sleazeball, but at least he's not as evil as Greve.
What also makes the film satisfying is that the minor characters are so well drawn, including Brown's two women, and, most notably, his partner-in-crime Ove Kjikerud (played by Eivind Sander) who is reluctant to give up his weekend with his Russian hooker to help perpetrate the crime that will inevitably, and literally in Brown's case, land them in the brown stuff.