"Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away."
- Antoine de Saint-Exupery
As a fan of this series, I should point out that this book is the best example of why these types of series tend to run on so much longer than planned. Authors like to claim that it "just gets away from them", but this book is an example that proves such claims false. The reality, I suspect, is that it's very hard to write a successful series and once you've got one, you want to stretch it out as long as possible to make the most money you can on it. There's not a thing wrong with that (assuming the story stays good, which in this book, it has not) but I don't want to hear any whining (as Martin is prone to) about how it just keeps "making itself longer".
Here we are introduced to many new characters and see little of the previous ones. While I don't doubt that some of these characters will lead interesting directions eventually, I weary of the stall tactic. Nearly everything important to wrapping up the story from the previous books in the series that appears in this book could have been put together in a chapter or two added to the previous book or the next one.
The whole book reads like exactly what it is: the author trying to stretch the series into more books than needed. Martin has many talents as a writer (interesting characters and good descriptions, for example), but he would do well to remember that sometimes more is not better. Sometimes it's just more.