Lethem is a New Yorker's author. Which is not to say that you need to be from NY to like him, but if you are, you will appreciate him all the more. We New Yorkers are a somewhat interesting bunch.
Anyway, the book itself is a great mystery/psychological novel with the right mix of character, plot and style. Or, to put another way, if Phillip Marlowe had had Tourettes, he would have been Lionel Essrog.