I just finished reading through Shadows Over Vathak and love the way they've mixed a Ravenloft vampiresque horror setting with Lovecraftian horror and integrated it with the strengths of the Pathfinder system. They swap in new races, including three human "races", and make them work; you can play the other core races but they are but remnants of their former glory here. There are also five new classes based on the setting. The gazetteer section is excellent and backed up with a great DM section which provides an array of material for running games in Vathak. So the bottom line is that if you're interested in a great fantasy horror setting then this book is for you. I think it's very usable (my Wednesday group is likely to experience it in the future) and definitely worth the money. (There's a much longer and detailed review on my blog at http://outremerdm.blogspot.com/2013/02/review-shadows-over-vathak.html)
I previously bought Osirion, Land of Pharaohs from Paizo and was rather disappointed--and thus almost made the mistake of not buying this top-notch work. My group just started playing the Shackled City adventure path, which is set in a jungle. Luckily for me, this book came out just after we started and it's perfect for really any jungle campaign. The wealth of detail on the many cities and key adventure sites is just right, plenty to explain what each is about but leaving room for the GM's imagination. There are also a lot of maps in different cool styles. The monsters at the back, unlike a lot of the new monsters I come across, are actually believable and useful and will definitely find a home in my campaign. The section on natural hazards is very well done and easy to use. The only bit I was left wanting more on was the info on various cultures of the area. However, the very wide coverage (with maps!) of the cities and sites more than made up for it.
I just got my pre-order today and I was very pleased with what came out of the box. The artwork is good, but the cards feel like they wont' stand as much wear as normal playing cards (but we'll see). I like that each card has a tactical use and a strategic/storyline use. I plan to introduce these to my players and see what the reaction is.
