This book has been recommended to me, and on my radar for a long, long time. I am extremely glad I finally got around to reading it!
The Blade Itself is in some ways a typical fantasy novel with magic, warriors, and romance. It takes the normal fantasy archetypes and builds on them in really interesting ways! I highly recommend this book, and will avoid spoilers in the following review.
The Blade Itself follows my favorite formula for fantasy. It has a diverse group of point of view characters, all across the setting, doing exciting things which will presumably all converge at some point throughout the series. Abercrombie does a really good job of making memorable characters. There are a lot of important people, some of whom seem superficially similar, but he does a good job making them all have distinct voices and compelling stories.
A major complaint I have about the series so far is that the magic is confusing and poorly defined. It's a little plot-devicy and nebulous. I think this might be a deliberate plot point, however, and might get pinned down later. Some of its vagueness is probably deliberate, since few people in the setting understand it. The source and methods will probably get fleshed out later, but so far it's a little like, "and then MAGIC happens" to solve some problems.
This is a very dark story, in a dark setting, full of dark characters. If you like Matthew Stover or George R.R. Martin this will probably work for you. It's pretty violent, lots of torture, swearing, etc. One of the main characters is a professional torturer, for example. Not a ton of sex or rape, but some is implied. The F-word is used quite a bit, but many characters use the word "fruits" for male genitals which cracks me up every time. That and "the cock rot" comes up a lot. Just putting that out there because it's funny, and this series is not for children.
This book will probably go over well with fans of fantasy who don't mind dark stuff. I wouldn't hesitate to recommend it to any fans of Game of Thrones. In a lot of ways it's more interesting and exciting than Game of Thrones, which honestly can be a little slow and gratuitous.