It's the second time I read this book. The last time was 6 years ago.
It's a great if you're already familiar with the GTD method since it connects the 5 steps workflow (capture, clarify, organize, reflect, engage) to the higher horizons (projects, areas of focus, goals, vision, purpose & principles). So it's the glue between Control and Perspective.
I loved re-reading it. It gave me some powerful insights and a deeper understanding of the GTD processes and how it can evolve over time.