The last two books are all the damn over the place. The last two seasons of television are an order of magnitude better than the last book in that the shows actually focus on shit that matters, rather than Tyrion's Endless River Roadtrip.
I've heard Dance with Dragons was rewritten entirely once because the first draft, one of his buddies said "but if X is with Y then this whole thing with Z is wrong" so he had to start over. It's also the book where the story goes from "expanding outward" to "wrapping up loose ends" which means he had to be a lot more precise with it. I kinda feel a lot of the important stuff got buried in chaff so it wouldn't be so obviously important.