A very satisfying mystery, which is a real page turner - I couldn't pick what was going to happen for the most part and the filmmakers cleverly play with expectations (introducing a character with a pregnant wife and heaps of backstory then killing him, setting it up as if Keith Carradine is going to die but then not doing it). Full of fresh touches - a deaf hit man and so on. Some brilliant suspense is created - I can't recall a series that had more tension, except maybe Game of Thrones.
Some drawbacks - it never made sense for me why Martin Freeman's character decided to take it to Billy Bob Thornton at the end; the scene where Freeman is bullied by the truck guy and is kids was far too over the top (the kid characters were done too broadly); Billy Bob's character was a bit too much of a superman at times (wiping out 23 mafia members at one time? being a dentist for six months to get close to a contact? really?); and that Australian mafia character in Minnesota was really annoying. Can Hollywood please stop putting Aussie characters randomly in things?
But overall this was excellent and I liked it a lot.