I'm probably going to buck the trend here and say that although it's quite a nice book to own, the patterns are great and I have the utmost respect for Oliver Edwards knowledge, skill and understanding ... I'm not that impressed.
From my perspective I don't think the total reliance on line drawing works - a mix of line drawings and photographs I feel would have been more successful - the line drawings swamp the pages.
In addition, when viewing the line drawings you need to appreciate that OE is a left handed tyer who ties by bringing the thread towards himself - to begin with I found myself wondering why some illustrations seemed to show that he'd reversed the thread direction ... then the penny dropped. I believe the majority of us tie right handed with the thread rotation away from us.
However, having said all that, the patterns are great and clearly well researched and the result of many years experience. He clearly is 'expert'.