I'm currently about a third of the way through and very much enjoying it.
I do remember why I didn't pick this one up straight away though. I am not really a fan of the whole underground supernatural fighting ring as a plot device. It's one that has been done over and over* and has never really appealed to me.
But I had forgotten how much I love the characters of this series, and so far it's much more about them. I am so glad that Ilona Andrews has a new series coming out shortly so I don't have to wait too long before getting my hands on another of her books.
* - Star Trek, Angel, Sanctuary, Torchwood. I'm sure there are others.