I read it years ago and thought it was wonderful. It's make a great movie, but the company, let alone Walt's descendents, would never allow that to happen.
It's a great book. I'd recommend it wholeheartedly. It's a great read with the added "what if Walt came back?" attraction for us fans.
My own novel, 'The Happiest Workplace On Earth', asks a similar question - "what if Walt hadn't died but had gone on to complete his vision of Epcot?"