This is currently my absolute favorite series. I loved the first book in the series, and this one is - if not quite as good - a very strong installment.
McGuire's world-buiding is amazing. I love her sense of humor, and Verity's light-hearted internal monologue is a treat. The suporting characters are also enjoyable. I liked Sarah in the first book. I loved her in this one. There is a brief moment in the middle of the book where we are treated to a first-person narrative inside her head, providing even more insight into her character.
The romance is natural and sweet. There were at least two "awwwww" moments in this book. The first, where Dominic declares his love for Verity and the second, when he shows up after Verity has been kidnapped, and it is clear that he has cut ties with everything that he thought was real and important because being with her and saving her has become the most important thing in the world to him.. The ending is pretty darned sweet, too.
I have no idea where McGuire finds the information about these cryptids, since she seems to literally have an endless supply of them. The most interesting one in this book was the manananggal, which I assumed had come out of her head until I wikipedia'd it. Whoa, Nelly. Us humans have some twisted imaginations for sure.
If I have one complaint, it is that Verity's internal monologue, while funny and engaging, can get a bit wearing. She is always ironic, always self-deprecating, and sometimes this tends to make her less "real" to me.
My still favorite thing about these books are (is?) the Aeslin mice. Haill the Colony and the Sacrament of the Rescue of the Arboreal Priestess. Totally brilliant. And fun.