Astonishingly good. Probably the best film I've seen so far this year. Olivia Colman deserves every award going, frankly.
Interesting to hear Paddy Considine's thoughts afterwards too, and of his desire to stay away from 'shaky camera social realism'. Although the subject matter (and Gary Oldman's involvement) may suggest Nil By Mouth as a precedent, I think that's a pretty lazy comparison to make, and based on subject matter alone, rather than narrative or directorial style. I was reminded of a blend of Eastwood's toughness and Nick Cave's fire and brimstone redemption.