I love the Carrion crown AP, and I'm a sucker for creepy stuff and horror. Therefore I had high expectations for this book. Unfortunately, it didn't deliver for me. The ideas for building atmosphere were nice, but not as compelling/great as GM ideas presented in the Gamemaster's guide.The history section was nice. For the cities and settlements I would have liked some more details on inhabitants, e.g. a in a few lines fleshed out inn/innkeeper/captain of the guard who captures the location. The note in introduction is something that really captured my attention, and I was hoping for more of that.
I'm a big fan of the Pathfinder game rules (core rule book, advanced player's guide, gamemaster guide, and the monster manuals) and adventure paths for their atmosphere and creativity. However a few products I bought, among others this one, don't bring this particular atmosphere that I came to expect. If you're thinking of buying this one, check first if it's really what you're after.