On my two re-reads of the first four books, AFFC was always much harder to read. I thought it was slow and kinda uneventful when I read the first time, but it only got worse on the re-reads. If I'll ever re-read this book again, I'll probably skip Brienne and Dorne chapters altogether. I fucking hate Dorne and every single useless character in this part of the story. Brienne's chapters show that war is hell, but we already know this from Arya's chapters in ACOK and ASOS. It's telling the same damn thing for the third time. We also know that Brienne's quest is entirely pointless because Sansa is in Eyrie, so all of her chapters exist to basically just make her suffer and get disfigured and executed (sort of) in the end. All we learn from her chapters is that Sandor is probably alive.
I really liked ADWD chapters that were set in Westeros, except Dorne and Jon Conninghton. All the Essos chapters just kill whatever momentum the book develops. There's Quentyn, the single most pointless character in the books, even more than that idiot Kingsguard from AFFC. Aegon exists only because Martin has no idea how to bring Daenerys to Westeros, so Aegon does what Daenerys should've done a long time ago. I guess it's much easier to invent a new character (or "resurrect" in Aegon's and Connighton's case) than untie the Meereenese knot. And then there are Tyrion's chapters where he either admires the local flora and fauna or gets abused. And finally, Daenerys - 12 or so chapters of her being a stupid teen, destroying any development she had in previous books. Her last chapter is so disgusting I'd like to "unread" it, if it were possible.