Just finished it. Oddly, the section of the book that I thought I would find the most interesting; from the redevelopment of Chessington onward didn't end up being my favourite part of the book. That doesn't mean that it's at all bad, I suppose it's just inevitable that as a fan of coasters and theme parks, not all of it was going to be new or surprising.
I think it's because that part of John's career is already documented so extensively by himself and others, it would be difficult to add to it without going into extremely nerdy detail which could put off the average reader, so it was probably the right decision.
The parts that I did find absolutely fascinating were John's accounts of his experiences and his work at the Windsor theatre, on various film sets and at Barry island. He really worked hard, showed unbelievable ingenuity and created his own opportunities through this. It was inspiring to read just how vast John's skill set is and how he would turn his hand to pretty much anything to make sure it was done properly.
I also enjoyed the beginning of the book that went over John's childhood influences, it gives a lot of context to the Wardley way of designing rides, particularly the Haunted House.
Overall, a great read, I wish there was more of it. I don't read many autobiographies but this one kept me thoroughly entertained.