While I'm not much of an intellectual I do take the study of Tibetan texts pretty seriously. What I especially like about this book is that Thinley Norbu Rinpoche has taken some of the most basic and at the same time most profound teachings of the Vajrayana and made them especially accessible to everyone. He begins the book's preface with a small quotation of Patrul Rinpoche;
"Those who intend to benefit others through holy teachings
Do not use elaborate terms and poetry.
The pure path is shown with the simple words of the laity.
That is the sublime method of the Bodhisattvas."
The book absolutely remains true to these words of advice. It can be picked up and read a bit at a time over days, months or years, as each chapter covers a different topic. It can be read sequentially or randomly and enjoyed. In some ways it reminds me a bit of the classic, "Cutting Through Spiritual Materialism" in that it is a book to be read again and again at intervals in ones life and I think it will remain fresh with each reading.
On a personal note, my copy lives in a zip-lock bag in my rucksack. I like having it around me to pick up and read a few lines whenever I have a free moment. It is like breathing fresh air and clarity.
Thinley Norbu's heart energy is expressed stainlessly in White Sail.. It is pure, direct essence of DzogChen. Read it every day forever; it will always be fresh.