The accompanying text, while a bit uncharacteristic (likely due to editorial consistency), is informative and comprehensive, giving you a great overview of Costa Rica, its history, its people, and places of interest. Its travel information, such as lodgings, appears targeted towards middle-class travelers, although it touches on a wide range of styles and budgets. And when you're ready to plan your itinerary the maps outshine those of any other guide book, and are good enough to use on your trip, even for 90% of the driving most folks are likely to do.
Other guidebooks might offer more in-depth and "insider" information with a particular slant (e.g. the excellent, down-to-earth, and environmentally conscious book by Harry S. Pariser, "Explore Costa Rica") but the Insight Guide should be the first one you buy to "see" where your travels might take you.