I'm not going to talk about the plot because if you're reading these reviews, you've likely already read the first three books in the series and want to know whether or not you should continue reading.
My vote would be YES. The writing style, the story, and the execution of this novel are just as good as the first three. Faith Hunter is still going strong. I start to worry about consistency in series and whether the author can keep creating interesting scenarios, conflicts, and resolutions without getting repetitive or boring. I also get annoyed when characters either don't grow or progress or conversely, if they have radical personality shifts or start doing things completely out of character for the sake of something new and interesting.
Faith Hunter brings back all of your favorite characters, and Jane is constantly progressing in her relationships and discovering more about her past and her identity. I like these stories because they don't get tied up all neatly at the end, and there isn't always a happy ending. The protagonist has to deal with being disliked, with hurting people she cares about, and with confronting her own nature. We get a few new characters and learn some new things, but there is also a great deal of familiarity here without it getting boring. Jane is kick-ass as always, but she has a lot of struggles in this novel and we get the sense that she will continue to struggle in future novels.
I'm impressed with this author's work, and I didn't want it to end. It reminds me a lot of the Kim Harrison series Dead Witch Walking (The Hollows, Book 1). There are many characters and a lot of action and sub-plots. The result is that you don't have just one climax to the action - rather the storyline peaks multiple times because Jane is always dealing with more than one situation that only somewhat overlap. It's more like real-life in that way.
I really wish that I wasn't caught up in this series, because I would love to read another one right now. I hope the action keeps going for a long time. Faith Hunter has created a great world here and a fabulous protagonist in Jane and Beast.