I was traveling with three friends to Andalucia and we used the guide daily. The information that it gave on sites like the Alcazar in Seville or the Mezquita in Cordoba were invaluable in placing the monuments and cities in time, context, and importance. All of us, including the non-history-geeks of the group, loved the explanations and information on the sites, and someone was always asking "who had the book" at many points throughout the day.
The guide was very nice to have along when we were looking for places to eat. We ate at least once a day at restaurants that were recommended and we were not disappointed at any meal.
The map and distance guide at the beginning of the book were quite helpful in planning our trips as we stayed in the vicinity of Malaga and drove back and forth to Seville, Cordoba, and Gibraltar. They came in handy on the way back from Seville when we decided to detour to Ronda to see the Puente Nueve. The maps also helped us decide where to park once we got into a city or provide us with directions when we didn't have a larger, more detailed map available to us.
The only thing that we had a problem with was that the areas covered by the maps were too small for detailed driving instructions. However, it's a guide so that's to be expected. Pairing the guide and a GPS system would be ideal.