I purchased this over the weekend and thought I'd share a few thoughts about it.

Mythical Monstrosities is a sourcebook detailing a new PC race, a race-specific base class, and several new monsters for Monte Cook's Arcana Evolved. A lot of the content seems inspired by Classical Greek mythology (which I enjoyed since I started developing an alternate pantheon based on the same thing). The Taurians are a really interesting race and fit in pretty well with the flavor of the Diamond Throne setting. Their tragic background makes for a lot of meat for a role-player to chew on, or they can fill in as an excellent adversary whose motivations tread deeply in that grey area that makes for really good non-villain adversaries.

I really like all the variant stats included in the book, making it a good resource for anyone still using 3.0-style DR, or alternate AC or HP systems, or a variety of other variant rules that are commonly encountered in 3.X D&D games. They're set off in their own text block so they don't clutter the standard stat block, which I really like because it's easy to ignore if you're not using any of those variant systems. I also enjoyed seeing Designer's Notes that talked about the creature's development and offered suggestions on how to use the creatures. The only thing I would like to have seen that wasn't in Mythical Monstrosities was racial levels for the Taurians (and maybe evolved levels for them). Perhaps that can be included in a web supplement in the future. The art was evocative and of higher quality that you might expect for something at this price point (indeed, just the fact that it has art is impressive for that price point), though as with most books, some of it is better quality than others. My only beef with the layout is that it's not particularly printer friendly. Clearly, it's preferred that you buy the P.O.D. version rather than the PDF and print it yourself. While I am anal-retentive enough to want something printer-friendly, I'm not OCD enough that it's going to stop me from printing the PDF myself and getting bound at a copy store; I can deal with the idiosyncrises that will occur when I have Acrobat fit it to the page, goodness knows I've done it with other companies' products.