It is an excellent book and huge. If you are planning on going there or want to know about the herpetofauna there then that book is a must. A smaller and less comprehensive book is by Twan Leenders "A field guide to the Amphibians and Reptiles of Costa Rica". It is much more compact and can be easily carried.
Both have excellent photos and info but Dr. Savage's is by far one of the best herp books on the market and is actually a cheap price for what you get. I own and thoroughly enjoy both.
Robert Jadin
www.snakeman1982.com