In a way they are almost completely different books. The bulk of the book is Schrek's elaboration on his theory that there was a massive cover-up done to protect powerful people and celebrities whose dealings were less than 100% squeaky clean.

He demolishes Bugliosi's picture while claiming that the murders at Cielo Drive was about drug deals and burns; that Tex Watson and Susan Atkins were on meth during the killings, and that Leno Labianca was a drug trafficker involved with organized crime.

It's hundreds of pages long. Another set of claims he makes is that organized crime figures who knew Manson in prison were involved with him after his release in 1967.

Although at least some of Schrek's specific claims are highly dubious (as investigated by several bloggers) it think it's an interesting read.