I've not read anything by Nalini Singh before. I know she has a very popular psy-changeling series (I'm not even sure what that means), but this is her first book for me.
Angels' Blood is a story of angels, vampires, and a vampire hunter. In this reality, vampires are created by angels and are bound to the angels for 100 years. Sometimes they try to escape before their time is up and that's where the vampire hunters come in. Elena is a vampire hunter called by an archangel, Raphael, to capture what she thinks is a vampire but turns out to be a rogue archangel. There is quite a bit of sexual attraction between Elena and Raphael; he's an archangel used to giving orders and she's quite the rebel who refuses to take orders.
I enjoyed the book but it's not a keeper for me. It took awhile for me to get into the story; I enjoyed the middle but by the end I was ready for it to be over. I can't really pinpoint what about it I didn't care for, but it just didn't reach out and grab me. There were no Too Stupid To Live moments, but she just seemed be obstinate for no good reason. Also, there was quite a bit of "remembered painful past" that the author never got into. That was kind of frustrating.