That is one good reason to read this book.
Another good reason is his ability to pick apart the familiar arguments against Nixon. You will read of the "smoking gun" taped conversation between the President and top aide H.R. "Bob" Haldeman. I had always thought that Nixon agreed with Haldeman to get the CIA to interfere with an FBI investigation of the Watergate hotel break-in. The author provides factual support for belief that Nixon simply wanted to protect the identities of Democratic contributors to his campaign.
And the storied "18 1/2 minute" gap on another tape? There may not have been anything of interest on it (although I am still curious as to why it was intentionally erased).
If you still think John Dean is a "good guy" in this matter, give this book a read.