I'll start with my Dislikes:
1. I find the entire Aegon storyline dissatisfying. It seems almost like it was grafted on to the main plot. The effort in doing this major retrofit might be the reason for the very long delay in publishing ADWD, and the real reason why the division between AFFC and ADWD was made by POV, rather than chronologically.
It's not that you can't explain or justify the reed-basket escape of baby Aegon, or the exiled Connington's resurgence. It can logically be made to work. But it's all quite a stretch.
Or is it possible that a reader could actually feel a sort of jealousy of a new major character?
2. While the Selmy pov's aren't bad, on the whole the Meereen chapters make tedious reading. These chapters are not valueless, since Danaerys is learning, as did Robb Stark or Robert Baratheon, that there's a big difference between being a puissant warlord, and becoming an effective monarch. Unfortunately the reader is made to follow Dany's flailing efforts in close detail.
The biggest problem here is that the there are no really compelling Ghiscari characters or scenes, despite the quite considerable amount of description devoted to them. I also find that Dany's handmaids are too predictable--e.g. has Missandei or Irri ever given the reader a surprise? The implicit Orientalism in ASOIAF might be said to take a toll on the story itself. As a result, the Westerosi in Meereen just seem to be marking time against a background that is bland despite the exotic furnishings.
There were a whole bunch of people converging nicely on Dany (Marwyn, Victarion, Quentyn, Tyrion, and now also Prince Aegon the Unlikeliest) but instead GRRM chose to delay.
As Varys once said to Illyrio, "Make haste, even the finest juggler cannot keep a hundred balls in the air forever." GRRM of course, as I'm sure Illyrio would agree, is no mere juggler, but a true sorceror!
3. A smaller complaint: I find it improbable that two or three thousand quality fighting men were still available in the North, who could, moreover, all be gathered together in one swoop. Sure, Cassel and Tallheart had been taken by surprise by the descent of the Ironmen and the treachery of Bolton, but why would they ever have been filling their ranks with the greenest boys in the first place, when real men could still be mustered from the hills? The only way I can justify it to myself is on account of the harvests.
4. Too many almost-deaths, too many "saving throws." It's no longer very suspenseful. More like, "Oh, now Tyrion fell in the river, I wonder who will pull him out?" or "Oh, Jonny got stabbed, I wonder how GRRM will make it so he lives?"
I never really believed that Davos or Brienne or Sandor perished.
But the thing that really sold me on this whole series, was when King Joffrey made poor Ned dance the funky chicken. "Aha!" I cried, "now this becomes truly interesting!"
5. I'm just a little bit disappointed that Jorah and Tyrion didn't get drunk together and share embarrassing ex-wife stories. "Tell me, where do whores go, Mormont?" Reply: "Imp, why don't you go ask Lynesse, she'd know all about it!"
Now for my likes:
1. Janos Slynt got the chop, and in fine style.
2. With Rorge, Biter, Hoat, & Tickler all gone, Ramsay Bolton proudly assumes the mantle of Number One Monster, even if GRRM does exhibit his long-suspected S & M tastes in some of the Theon chapters.
3. There is actually a whole volume in which a musician or singer doesn't get brutally tortured and murdered. There are only loving, wistful recollections of the scenes in which musicians or singers were brutally tortured or murdered--and the hint of another bard about to get flayed. I wonder whether GRRM once had a high-school sweetheart stolen by a guitar player or something, since ASOIAF is almost like Revenge of the Writer Against the Musicians.
4. Tyrion rides the Pig, while Cersei runs naked in the streets. Myrcella lost an ear. Kevan becomes further proof that King's Hand is the world's most dangerous job. GRRM makes the Lannisters suffer as cruelly as the Starks.
5. The fearful symmetry of the Sand Snakes sent out to work, each in the way best suited to her.