The final part of the CotCT AP is a little sandboxy and mainly describes the Castle of Korvosa (95 rooms). But we are not in front of a dungeon crawl here, because the PC will have the map of the entire place.
It is quite like this :
"Guys, you have to enter in the castle, find clues of the queen evilness and destroy the devils who may find there. How ? Well guys, everything is up to you. We NPCs will show and act only when it will be no longer dangerous".
And this is a little disappointing : the PCs are really on their own during both the castle exploration and the final part in the sunken queen, the main allies only act "off screen" and their actions and the rebellion are too shortly described. It is quite artificial.... but still greatly enjoyable.
The last part is great : I really love the fact that the end part of the story is set in a flooded dungeon, with aquatic fights. I also like the use of the blood pool ("oh look, there's a queen in a giant bubble of blood !", the references to Thassilon and the "false" awakening of the dragon.
The article on Kazavon provides many hooks to enhance and continue the story.
I'm not fond of dungeon crawling in general and I trully dislike huge dungeons. When there are 3 fights in a 5-6h hours game session, for me as a DM there are too many fights.
This AP volume "only" describe one huge dungeon with many fights, so at first it seems that it is definitally not my cup of tea. The book is quite boring to read with the detailed descriptions of all the rooms.
But I have to be fair : for groups who love dungeon crawls, Skeletons of Scarwall must be a masterpiece. The design level is far far better than Jorgenfist in AP4 or the Runeforge in AP5. A real ambiance radiates from this place, a dark and breathtaking ambiance with creepy haunts everywhere. If the DM removes most of the minor figths and if the players like this play style, it can be a blast to run.
Still, I prefer the way the Skinsaw Murders bring mystery and horror to the game than that "every undead bosses must be destroy" approach.
The Belkzen article is useful and give some ideas. The Zon Kuthon article is amazing... creepy and disgusting indeed, but amazing.
I give 3/5 for the adventure itself and +1 for the support articles. So 4/5.
This volume is all about shoanti. In this volume, there is no "boring-linear-fighting-only-encounters-when-we-travel-from-A-to-B" and no dungeon ! Just a deep immersion in an exotic and rich culture in a land with uncommon features. Heavy on roleplaying and supported with nice articles. This part is truly refreshing... despite its title. :)
On one side, I like the pig game, Laori Vaus character and the use of a galtan final blade.
The article on rakshasas give depth on creatures I had no interest before.
On the other side, the whole Arkona thing (and how Golio acts during this part of the story) is poorly handled for me.
Glorio's cover is totally exposed when he sends the PCs in the labyrinth. It seems not enough subtle from a rakshasa leader, politically too risky. And honestly if he really wants to kill his sister, he can do it himself without involving anyone, especially not the PCs.
Futhermore, the idea of a "rotating dungeon" might seem nice on paper, but in practice I don't see how I can handle that in a game session.
This AP volume is a jewel. You will find everything in it : deep NPCs, complex gray clergy (Abadar), corrupted authorities, mad evil cultists, fight against time, rich story with plot twists, epic final battle... Everything, really, is highly enjoyable. I don't see a major negative point here and I'm usually not a crazy paizo fan boy.