I have used the all-encopmassing "South American Handbook" also by Footprint with great success, and this was my first attempt at a specific country guide. I was impressed with the useful and in-depth information regarding each city or town that I visited. The accommodation, food, and entertainment suggestions were spot-on and always just as it said.
The only thing lacking for me was the, um, somewhat skimpy coverage of some of the ancient sites. For example, the suggestion to take a taxi to the ruins of Tambo Machay and walking down to the city (Cuzco) was wonderful, but information pertaining to the specific sites on the way down (Tambo Machay, Puca Pucara, Quengo, and Sacsaywahyman) was restricted to a sentence (or less) each.
Low down: if you want spot-on guidebook for lodging, food, and entertainment listings, and are not as interested in the cultural sites, ruins, museums, and other things to do, this would be a perfect book. If you do want more of the ruins, cultural sites, etc., I would suggest another supplemental guide, perhaps.