It gives you a clear idea of what is required to pass the CCIE lab exam. It dispels myths and it provides sound advice, for example on how to fund the endeavor.
I think that the biggest contribution it makes is to save you time and money, by showing you which pitfalls to avoid. You now know that you need to focus your studies and don’t need to read every page of every text book for example.
The personal viewpoint, and details on when to book your exams, is very helpful.