There's something about all detective novels that provide a very nice pace for the prospective reader, a gentle lulling between beatings and the solving of murders, and this is only enhanced by the inclusion of ghosts and Succubi. 
 I only learned later into the reading of this that he's the author of other Constantine stories, so my initial connection made perfect sense. Hell, I like Constantine, so this is pretty much perfect for me. 
 I know I'm going to like the rest of the series, if this is a good sample. Fun stuff.