So, after my experience with Kobold Press' "Tome of Beasts" (reviewed elsewhere) I began a search locally at my Friendly Local Game Store (FLGS) to find other Kobold Press editions.
What I ended up buying was the "Advanced Races Compendium" - a book created to allow Player Characters to choose from over 20 new races for Pathfinder/ So, I bought it. What a tome again! 336 pages (with three pages of ads for other Kobold Press books). Over twenty new races possibly for players. However, I found that I probably would not use the vast majority of these races for PC's. Certainty the more evil races should always be NPC's - but the rules for evil races in this book allow for great customization for the GM.
Everything from Aasimars to Werelions - but a few should have been better off in the Appendix - which includes much shorter write ups of four races. Also, a couple of the detailed races should have gone into the Appendix and good races brought out to expanded write ups. If it had been me, I would have shortened the "Werelion" section to the Appendix, and enlarged the Kitsune.
Kobold Press has done a decent job of converting these unusual choices to characters that would not overbalance a game. The Centaurs section is my personal favorite. About 10 pages of gorgeous art an equal amount for statistics. Lizardfolk would probably become Serpentfolk in my campaign. Then, somewhere, there is a Kitsune settlement or two. The Drow section took me back to my first real exposure to D&D, where I played a half-Drow/Half-Human hybrid that =hated= Drow because they had raped his mother and, oddly enough, conceived him.
Overall, this is just about as nice a book as the fantastic Tome of Beasts (5th Edition). Every Pathfinder GM should at least take a look at it. One of my highest recommendations. If i was allowed, I'd give it 4 1/2 stars for including a couple races that should have been relegated to the Appendix, and at least one race in the Appendix that should have been one of the choices for expansion to a full entry.