I participated in a Dharma center reading group that discussed this book, meeting twice a month. We took maybe a year and a half to go through the book slowly. The reading seeded some great discussion that enriched everyone. It's a book you can go back and read again and again. It is surely a desert island book, i.e. if you could only have one book for the rest of your life, this would be a top contender.

The commentary is written from notes on teachings by Paltrul Rinpoche, the great 19th Century teacher in eastern Tibet. ( )