Do a controlled test
If you could travel back in time say 30 years and buy 3 different brands of trailers and subject them to the consumer reports of identical tests. Then skip ahead 5 then 10 then another 15 years and compare each one at the different stages of aging, I think you would find the Airstream would win over time and the other units would have long made it to the landfill.
Say one of the tests was that the trailer was pulled over 30,000 miles across the Country. Another might be that a couple lived in it for 5 years. Another would test the exterior condition and another the interior.
Another big test would be to determine the value of the trailer and resale value at the 5, 10, 15, and 30 year marks. I was surprised to learn that the $8,000 I paid for my 72 Trade wind was more than the original owner paid for it new back in 1972!