Gray is one of those writers that I enjoy, in spite of his flaws. This book is no exception to this. Some of the discussion of history is questionable, but overall the book is not harmed by it.
For me, the important part of the book is the philosophy and metaphysics that the author presents. I enjoy the way that he reasons based on the information that he presents, and even if I may have a dispute with his starting point, I enjoy the journey and some aspect of his conclusions ring true.