I really liked A Feast for Crows
. Sure, it has some boring chapters, but all the books did (Brienne's stuff isn't worse than Arya's in earlier books); but the King's Landing stuff is top notch*, Arya finally gets an arc worth the character's time and the 'Alayne' stuff is also great.
And then on the sidelines we spend more time with the Vikings of the Iron Islands, who are fun, and Aeron Damphair is completely, wonderfully bonkers.
The book also includes by far the most interesting look at the Faith of the Seven, which doesn't hurt.
I don't think the idea of splitting the books in two was great and that does hurt it structurall but the actual content of book four I found consistent with the strengths and weaknesses of the earlier books and a similarly breezy read.
I've been planning on reading this series for a while since I don't have hbo and love high fantasy and vampires.
Never thought of it like that.
*Granted, King's Landing is usually the best stuff of any given book so that's no surprise.