This is by far the best campaign world book I have purchased in years. Some comparisons have been made to the “old gray box” Forgotten Realms Campaign Setting; that comparison is not undeserved. I believe this book blows away the Forgotten Realms Campaign Guides for D&D Fourth Edition and perhaps even Third Edition. It has to offer a lot of diversity, which appeals to me greatly. It even has a place for us Ravenloft fans: Ustalav. Paizo shows that large font type and large full-color pictures on every page are not what is needed to create a quality product (though they have plenty of beautiful illustrations, maps and heraldry). What is needed is detail and polish, and this book has plenty of both.
Outside of Dungeons & Dragons/Pathfinder, I have read campaign books for a variety of fantasy games and worlds. Some of these include Legend of the Five Rings, Talislanta, Earthdawn, and Exalted. I would say that the Pathfinder Chronicles Campaign Setting has all the richness of a complex setting like Talislanta, but it does not overwhelm the newcomer with information overload. It is well organized, beautifully illustrated, and edited very well.
Indeed, I will go out on a limb and say this is indeed the best campaign book I have ever purchased. I plan on putting this campaign world any many of the Pathfinder adventures to use in my current D&D 4E game and any future D&D 3.x/Pathfinder games.
