Just finished the first series (it's on the US Netflix) and really thought it was excellent. Particularly love that in addition to the main theme there is a Nick Cave song in every episode
It felt a bit like a cross between Deadwood and The Sopranos. Great cast and terrific writing, my favourite moments are the tense scenes of enemies at a table talking/threatening each other.
Going to start series 2 in a bit. Unfortunately S2 is not on Netflix so I had to resort to torrents.