I did enjoy the artwork of this book, finding it to be very crisp and vivid in most cases.
The presented specimens were also well-described and I thought they presented a fairly good assortment of setting-specific adversaries (allies?) for players looking for a fresh batch of inhabitants for their campaign.
That said, where this book fell down for me was that it didn't take enough risks. The 'new' subgroups just didn't inspire my imagination, which is ultimately what I personally look for in a bestiary/magic item compendium/setting rulebook. The minutiae is fine, but having a set of hardened 'guideposts' in the form of major NPCs, magic systems, or new subraces is essential for me to re-read these books. I just don't find myself doing that with this one.
Which is not to say that it's not a good book; I think it slots in just fine next to the others on my shelf. But I don't pick it out specifically to pore over its listed monsters when I'm looking for inspiration, which I do find myself doing with other books like the early Sword & Sorcery books and many of the Eberron books.