First, I would just like to say that Moleskines are fantastic little books--the city guides are no exception. I have ones for London and New York as well, and they have been invaluable for getting around and for storing notes and memories. Truly as marketed--they are better than most travel guides, because you, the traveler, create the adventure.
Atlanta's City Journal is well-made, and contains the usual components of the city book. My only complaint is the map. It's well-detailed and accurate, but is a little limited. Many of Atlanta's charms are found east of Downtown and Midtown, inside of the I-285 perimeter: most commonly, the areas surrounding Decatur. However, those areas are not showcased on the detailed "zoom-in" pages, which is a little unfortunate. I would have loved to painstakingly map out each little kitschy shop and dive bar over the months. Sure, it can be argued that Decatur is a separate city, but for the visitor or resident, this neighborhood is interchangeable with the city itself.
This won't mean much if you're not familiar with Atlanta, but the detailed maps only go as far east as Moreland Ave., just managing to fit in Little Five Points.
Still, that complaint is relatively small and I'm a little picky (biased, even--I live in the Decatur area, so I would have especially loved it). All in all, it's a great little book, and I still use it like crazy. Definately worth picking up if you're visiting or moving to ATL.