1) there are a ton of characters, so many that it was sometimes hard to keep up with who is related to whom and what role they have/had in the story.
2) some of the conversations are pretty trite.
Other than that, the action is great. The politics are intricate, as one would expect in 1599 AD and 1999 AD when dealing with vampires. I really enjoyed the historical aspect of the book, especially the male/female roles in 1599. The interweaving of Dracula and Yasamin throughout the book in every major event in history is great.
This would be a good read for people who enjoy urban fantasy, vampire books with a good historical background, and thrillers.