I'm surprised at how comprehensive this little guide is. Having lived in, and subsequently visited San Antonio many times, I can assure you that the best sites are included here. The catagories are nice and varied for travelers of all tastes. History, food, amusement parks, art, outdoors... it's all here. This book is all about the listings themselves, so don't expect much narrative content.
As one reviewer has already noted, the emphasis is on San Antonio, as it really should be, since it's the real tourist draw. Someday, guidebook editors will quick lumping Austin in with San Antonio, realizing that they are vastly different types of cities. While San Antonio feels like a Mexican New Orleans, Austin is more like a Texas version of San Diego. Austin is modern, active and hip, centered on the University of Texas and the 6th Street music scene. San Antonio is old, slow and hedonistic, with a much more diverse selection of tourist opportunities.
Buy this book as an efficient itinerary planner.