I found this book to be a mixed bag and just barely worth the price of the PDF.
The first 3 chapters present every race that can be a PC and gives you a whole slew (yes, slew) of options for customizing each race. I found the majority of the options to be both useful and flavorful. All of these races are previously available, but it is convenient to have all the races in one book when you are creating your character. Of course, if you have access to modern technology in the form of a laptop full of PDFs or even a 3G smartphone, then the luxury of one book of races becomes slightly less impressive.
The fourth chapter is where things go downhill. The more I use their race creation system, the more I just plain dislike it for making balanced PCs. I disliked it during the play test and I dislike it more now. I build a lot of custom PC races for my campaigns, so I'm feeling more than a little let down by this part of the book. Another race building system was devised on the Paizo forums that blows this one out of the water, in my opinion. On the other hand, if I need to slap together a "savage" NPC or monstrous BBEG, I will probably use this system. So it's got that going for it, I guess.
The artwork is excellent, by the way. Every race gets a nice picture and the cool new monsters that Paizo tries to pass off as example races are especially cool.
