Well all and all, the product is fairly solid. As others have mentioned the art is highly variable in quality. Xxyth are the primary reason to by the book in my opinion. Their entry has some of the best art and the content dovetails nicely to other products like WoTC's Fiend Folio, Eberron (the Qu'ori) and Lords of Madness. And they also have a customizable format similar to the core MM's dragon layout. With some of the other chaotic and strange aberrations you could base a whole campaign arc in twisted madness.

A durable hard cover, solid feats, interesting spells and, full-color. Forgive the artwork and the lack of 3.5 psionics (they are a no brainer to convert) and it is a STEAL at $10.

Still needs a little bit of work though. The good stuff first though.

The Good
Very inventive creatures. I have no familiarity at all with the Violet Dawn setting, so I enjoyed it strictly as a bestiary, and damn me if some of these things would be awesome to use in any number of campaign settings. Xoriat for Eberron, the Far Realms for Forgotten Realms/Greyhawk, the Maelstrom for Golarion. Intriguing creatures. I imagined a use for a good portion of the creatures included. There are some new spells, items, and magic items included - a nice bonus that supports the creatures it regards. Also, each page has a shield icon which lists the Challenge Rating of the creature - very handy when you're flipping through the book.

The Bad
Psionic creatures did not get left out (which is good), but they seem to have failed to update it to the 3.5 ruleset, making reference to attack and defensive modes. Some adjustment will be necessary. Some of the creatures look like they might have needed another editing pass.

The Ugly
The art varies from good to um, crappy. If you're looking for Wayne Reynolds or Todd Lockwood, it's not in this book. I'm disappointed in the presentation of some of the creatures, as they looked rushed instead of finished.

Overall, yes, worth buying, and at $10 it is a great bargain, though I don't know if I would have paid full price for it.

Bonus: The creatures are Open Game Content.