I could not put it down. It hit me at some point that I was at the intersection of readability and scholarship. Clearly the value of this book lies beyond its readability: Gottlieb is both a philosopher and a journalist (in the good sense), not a journalist who writes about philosophy. He investigates and provides a fresh look at the material: For instance what we bemoan as the flaws of Aristotelianism during the scholastic period came 2000 years after his work. Aristotle had an empirical bent --his followers are the ones to blame.
I liked his constant questioning of the labels put on philosophers and philosophies by the second hand readers.
Clearly he missed a few authors who deserve real coverage like Algazali, but I take what I can get.
The only other readable history of philosophy is Russell's. This one was less hurriedly put together.

Someone should bug the author to hurry with the sequel on Locke, Hume, etc.