In general, the concepts and ideas are pretty solid. A lot of common sense that revolves around using sunlight to help with sleep patterns. Somehow I personally experienced a similar sleeping pattern (sticking to a regular alarm, getting up quickly, getting sunlight) and it worked incredibly well for me for 2 years (until I broke the pattern).
The body of the book though is littered with how the author works with top sports teams, Manchester United, Man City, Arsenal, etc - top cyclists etc. I was happily convinced of his authority by chapter 1, but I didn't need repeated on every chapter. It felt like random name dropping (since most of the sports celebrities named were unknown to me).
All in all, there are some useful tips throughout the book, but probably didn't need so much of the constant reminders of who the author worked with.