This was really the last book I read in 2009, but it was close enough that I'm going to call it my first book of 2010.
On the positive side, Connelly does some things in 9 Dragons that set up the Harry Bosch series well for the novels to come. Unfortunately, it's impossible to talk about those things without dropping major spoilers on the unsuspecting reader.
On the negative side, the bulk of the action takes place outside of Los Angeles...way outside - Hong Kong, to be specific. Bosch's daughter has been kidnapped, possibly as the result of a case that Harry is working in L.A., and he immediately flies over to join Eleanor Wish in a frantic search for her. Previous Bosch novels have spent time in Las Vegas, so there's no hard and fast rule that Los Angeles has to be a major character in every Bosch book, but Hong Kong is a stretch. There are things to like about the "fish out of water" aspects of the story, but in this case Harry is so far out of his element that he doesn't seem quite like Harry.
It's not a bad book by any stretch of the imagination, and as previously noted sets up some nice things for the books to come. But overall, this is not one of the best Bosch books - probably middle of the pack, if not a bit lower.