In the AZ heat and sun they don't last long either.
I had a friend that took his two year old trailer camping with our group and when he set up, both pigtails were leaking, but one was just barely showing a bubble from a soap test. He had a manual regulator change over regulator with a Tee on the bottom for both hoses. The problem was that he couldn't shut off one side. We couldn't get parts late at night, so I ended up taking off one of my soft drawn copper pigtails and letting him use it to replace the one that he had that was leaking real bad. Since I had an automatic change over regulator I could run off of just one side. If for no other reason, the auto change over regulator is worth it.
I use the soft drawn copper pigtails. They could eventually work harden and crack, but I have never had one go bad yet. Besides, they are on the outside and they last much longer than any hose that I've ever had.
Ford F-350 4x4 Diesel
1988 Avion Triple Axle Trailer
1969 Avion C-11 Camper