This is a well-written, well-organized book. It appears to be an attempt to make Dzogchen teaching more accessible, for example, via the episodes from early in Namkhai Norbu's life.
Direct, written teachings of Dzogchen seem to be highly concentrated and mind-blowing, for example "Self-Liberation through Seeing with Naked Awareness", an old text translated by John M. Reynolds and Norbu's own "The Mirror". Each of these texts is accompanied by less terse commentary. It seems to be the expectation that any student of Dzogchen would also receive instruction ("transmission") from a Dzogchen teacher, to account for individual differences between students and, presumably, to help clear up whatever confusion the written texts may have led to. Dzogchen seems to be a substantial challenge, said in not too many words but not unlikely leading to a wealth of questions. A book like this one, "The Crystal and the Way of Light", probably functions to lessen the intensity and make the teaching more comfortable, at least until one is ready to face the challenge of the core teaching.
Despite the formidable challenge of Dzogchen, it is a teaching that emphasizes relaxation and acceptance. I've had no personal instruction in Dzogchen and it may be for those who do it seems substantially less confusing and overwhelming than it has for me. Judging from the number of books by him and in which he has supplied commentary, Norbu seems to be doing a great deal to make Dzogchen more accessible. His Dzogchen Community has chapters around the world.
This book seems a good introduction to Dzogchen, which is a curious and perhaps contradictory mix of mindfulness (to the extreme) and magic (e.g. the rainbow body). The teaching seems well-packaged, with an emphasis on amazement. Dzogchen can be found within Buddhism but also within Bon, another Tibetan religion. It's unclear to what extent Dzogchen elements were brought from Buddhism into Bon (and vice versa). Nevertheless, Dzogchen talk of awareness seems to mostly map into Thervada talk of mindfulness, with some "enhancements" in positive imagery like the sky, rainbows, and crystals.
Whether any of Norbu's books or teachings or any other on Dzogchen can help get you to this "magnificent sameness" I don't know. It seems attractive but I seem to need a more step by step approach and wonder about this big wow approach. Although Dzogchen is supposedly beyond institutional and cultural barriers, Norbu's Dzogchen Community seems heavily attached to Tibetan forms.
I recommend this book to anyone sincerely interested in Dzogchen teaching. The author, Namkhai Norbu Rinpoche, is a worlwide renouned teacher, scholar and above all a Dzogchen practitioner. Not only he expounds the theoretical basis of the teaching, he gives us a lot of examples from his own life of practice. WARNING: THIS BOOK IS DANGEROUS FOR YOUR EGO!!!