I'd definitely have to say I'm not disappointed with this book (PDF actually, book didn't show up yet). With this book Paizo has delivered some fantastic new classes who each have an interesting flavor, and all of them have some distinct and varied archetypes. Even a few older classes received love from this book with new archetypes for the alchemists, cavaliers, and witches among others. I can say I'll definitely be having some fun with the new content which released right before a friend is starting a new evil campaign (Spiritualist seems like a fine pick for a necromancer).
I've always found Numeria to be rather mysterious and information on it has always been rather vague up until now. This book has shed a lot of light on a very interesting setting and I couldn't have been more pleased with what was revealed. A very interesting read and worth the money.
