This book was quite strong, despite the definite "second book of a trilogy" feel it had. There was a lot of travel, and a lot of exposition (although the exposition was actually handled quite deftly). There was also an extremely typical Tolkien-esque quest which occupied the most central characters of the tale, and that went on for the entire novel, although Abercrombie thankfully subverts that tired trope in the end. In truth, I wasn't terribly impressed with the plot, either. It was reminiscent of Martin, but more predictable in many ways.
I was, however, very impressed with the character development. This is clearly one of Abercrombie's key strengths as a writer, and he makes extensive use of it in this novel. Every character in this book changes in a meaningful way, unfolding for the reader and letting colours show that hadn't been glimpsed in the first book of the series. Inquisitor Glokta, in particular, has developed from an interesting character into a brilliant and fascinating one, a deeply troubled Severian-meets-Tyrion Lannister (actually, his defence of the besieged city Dagoska recalled to me Tyrion's defence of King's Landing).
I love what Abercrombie brings to the table in this book, although I still think I prefer The Heroes. The combat was very good in this one, better than in The Blade Itself. Abercrombie keeps the darkness inherent in the story from becoming overwhelming with a liberal application of humour (dark humour, for the most part, but some undeniably funny stuff). There is also a definite undercurrent of class-consciousness which informed the politics in this novel, and being a class-minded kind of guy, I especially appreciated that aspect of the story.
Though this book isn't the best Joe Abercrombie can do, it's still pretty damn good.