I had 4 days in Athens last week. First time - half business, half pleasure.
The overall information in this "Best Of" is useful and concise, and comes in a handy bag sized format (or trouser pocket if you wear baggies). There are plenty of itineraries from "24 hours in Athens - must sees" to day excursions outside of the city, and some pleasant walks taking in the main sights and areas. I found the travel detail particularly useful - metro map, and guide to pricing and timings (a godsend actually, as I would not have dared brave it if I'd not had this guide - with prices starting from 70cents, the metro is a lot cheaper than a cab).
There's good information on each of the areas in Athens - Psiri, Plaka, Monastiraki, Kolonaki, Omonia, Piraeus, to name but a few, and the mini maps within the coverpages of the book were an absolute blessing when out and about.
My only annoyance with this guide (Feb 2007 edition) is that I spent an hour wandering around Plaka trying to find 'Eden' (the "only vegetarian restaurant in Athens") to be told by a kindly local that it had closed down five years ago. I know restaurants and bars come and go, but I thought 5 years was a touch ridiculous for out of date information. My learning-point there would be to phone first!
Overall though, this book helped me to get that little bit more out of my trip - nothing quite like reading a brief history of the Parthenon whilst sat in the shade of it!
As a "Best of" edition, obviously this guide only provides an overview to the City of Gods, and for a weekend break, or carrying around during the day, this book is the ideal travelling companion. I would also recommend the Insights guide to Athens, which is a heavier book, but more in depth.
And if you're reading this, I guess you're planning a trip to Athens - I hope you have a great time. It really is a unique place!