This book held a lot of credibility with me. First, Feynman was a singular individual, unswayed by pomposity and false pretenses, with no hidden agenda, and little desire to have other people like him - a rare thing. Second, the book is poorly written. The editors, on purpose, left it raw and unrefined, just as Feynman spoke it, to let more of Feynman come across. The result is uneven, jarring, and a little hard to read, and this, to me, is a good thing. Whenever I see fresh, sparkling, vibrant prose I don't believe it, because show me a more effective speaker than Hitler or a more electrifying call to action than the "Communist Manifesto". Without the swaying torrent of rhetoric, the message of the book stands on its own merrit.
Read this book. You'll walk away from it a little wiser.
Feynman is a remarkable character, which many virtues and flaws which are readily detectable in the book. It is a short, quick read that left me wanting to learn more about him.