Its a good book and very informative as far as New York City (and the underworld) goes. Lots of little-known info (i.e. local addresses) is listed here.
Its author, Patrick Downey, appeared at the "Gangster Convention" that some of us attended near Chicago in Sept., 2004. He was there selling his book. (I had already bought a copy before that and had saved myself some money... you can find it online selling for a lot less than its cover price).