The word "fiberglass" is one of those buzz words that is used to help sell product. Kind of like "low fat" "organic", "low sodium" etc. The trailers most of the forum members own are MOLDED
fiberglass and the egg like shell is 2 pieces of molded
fiberglass and the "shell" of the egg provides much of the structural support. The Airflyte and many others are fiberglass panels with numerous seams on a framework made from wood or metal and are much more likely to leak.
Molded fiberglass construction takes more time but it is much stronger and has much higher resale as well as a much more limited supply. Good luck in your search. Molded fiberglass costs more but in my mind, it's well worth the expense and the wait.