I don't have much a track record for reading biographies, so I can't judge this book against many others. But I do know that I thoroughly enjoyed it.
Having read most of Feynman's own materials (albeit stuff that was knocked into shape by others) and having viewed his messenger lectures (thanks to Bill Gates - well done Bill) like a giggling twit, you can guess that I am already a fan of the guy.
I think that the fact this book took some of the gloss and polish away from some of his better known adventures just made him all the more human and likeable and certainly didn't make me feel like the wizards curtain had been pulled to one side.
The book is easy to read yet comprehensive and detailed. Told with brutal honesty and yet still sensitively written and far more than a simple recounting of diary dates and events.
PS the science is great too.
Four out of five stars.