The initial chapters are most useful in understanding the concept of cyclical existence perpetuated by ignorance and the opportunity to escape through reducing that ignorance. Later sections on introspective and outward altruism are also engaging.
However, later sections on the practice of yoga and high yoga get very tangled in themselves, a profusion of jargon, and cites from other teachings. The last third of the book is either not for the uninitiated, obscure, or lost in translation.