This book is a factual account of the birth, rise and finally the demise of the Mafia. It is very to the point and rushed, considering the author wanted to cover the entire history in around 400 pages. There are so many interesting Dons, that I think, a book can be easily dedicated to the life of each Don. There are books, of course, inspired by some already (The Godfather, Al Copone), but a proper series can be written. It would be really difficult due to the Omerta, but, it would be really interesting.
Although, the subject of this book is very morbid, due to the blunt factual tone, most of the horror just passes over you. You don't feel any horror or shock or revulsion. You just... read it. Like its alright.
All in all, informative and enlightening.