This book on it's own was fairly slow, but still interesting enough to not be boring. As things continue through the rest of the series, however, the characters get much more developed and the books get harder and harder to put down. The plots are intriguing and creative, and I greatly enjoyed the fact that mobs were used as actual important characters, rather than simply being used as cannon fodder for the good guys. Overall, I think this series is good for pretty much anyone who enjoys quick reads and enjoyable characters.
I especially liked Erebus. I mean, who doesn't? :)