I thought this book was an interesting mix between Sherlock Holmes and Ghostbusters. The scenes where they encountered ghosts were definitely my favorite. There were also plenty of little side mysteries to keep you guessing. I figured out the main mystery well before the end, but I was still left guessing at certain points.
On a side note, I think the character development could have been a bit stronger. I liked Lucy, but I don't feel as though I fully connected with her. George was certainly portrayed as an annoying buffoon and it must have worked because I certainly viewed him as such. He got a little better toward the end, but he essentially wasn't portrayed in a very pleasing light. Lockwood was definitely broody and had quicksilver mood swings, which certainly fits a Sherlock Holmes type of character.
Overall, I really enjoyed this book and think it's a definite must read for those interested in ghosts and things that go bump in the night. I'm definitely looking forward to reading other books in this series!