This book is great if you are already familiar with the subject and have read other books such as Joe Pistone's Donnie Brasco or Maas' The Valachi Papers.
Here, the author draws a great deal from those sources to the point where, in several instances, quotes word from word from "The Valachi Papers", a seminal work on the inner workings of the Mafia.
The great thing about this book is that it brings the story of the Mafia up to date, as late as 2004, and puts into historical context the isolated events related in Pistone or Maas books. Like many other works on the sujbect, King of the Godfathers starts with a historical setting and background prior to Massino entering the Mafia as a Bonano soldier.
Howerver, what I found most interesting about this book is the insight into how little the US Government and the FBI knew about the Mafia until the late seventies and how crucial Joe Pistone's work as an undercorve agent was to bring down organised crime in the US and why drug trafficking, even though it presented the greatest chance for profits, proved to be the ultimate doom of the US Mafia.