The book is ok, though not great in terms of a study guide for the PMI Test, which is the primary reason for my purchase.
It does provide a good overview & discussion on the topics it covers, but it doesn't cover everything outlined in the PMBOK Guide.
Because it doesn't cover all topics, this book doesn't add significant value as a study guide for the PMI Exam. The book would be a good overview/discussion book on the topics covered as it gives various "expert" writings on the issues examined.
As an official PMI Publication, I assumed it would cover all topics in the PMBOK. I guess this is what happens when we shop virtually vs brick/mortar.