If the question is which construction is bigger, stronger, jumps higher, runs faster, last longer? There is no right answer.
Some people keep their TTs decades, others about 6 or 7 years. Some folks are so enamored with older units they restore them or buy retro models. New models abound every year as do new construction materials and techniques. Most of this is cost driven.
Aluminum, the so called stick and tin, as stood the test of time and is not going away any time soon. Fiberglass and other smooth sided materials have also been around for decades. Their materials allows more modern shapes and provides an easel for some fantastic art work.
Like roof materials, windows, frames, axles and other TT items, the manufacturer uses what they feel are the most appropriate for the market share they are trying to capture.
Fortunately for the TT buyer, they can pick and choose as they see fit.
