Higher performance is one reason.
If you want to build an airplane, making the proper choice is the most important decision you must face. You must consider what materials you are best suited to work with. There are so many questions to be answered. From the foreword by Tom Poberezny, President of the Experimental Aircraft Association Reading this book could prevent you from starting a multi-year project you won't finish, or from making mistakes that could cost thousands. If you don't agree, just return it within 30 days for a full refund.