They're tough guns. I would like to see what the polymer breakdown over long periods of time would be. But who has their gun exposed to sunlight constantly, like a car dashboard in an Arizona parking lot? Mine sits in a dark safe forever, and when it comes out to play, it gets cased and transported to a dark building. Come to think of it, I don't think my Glock has ever seen sunshine besides being cleaned on the kitchen table on a summer's the afternoon.
In actuality, the closest my 21SF comes to a "torture test" is when I fire 80 rounds at the range then don't clean it when I get home for a couple more range visits.
Glock plastic is good to go and passes NATO mil spec
I bought a Glock to USE. If I forget to clean it once in a while and scuff it up...so be it. So far it hasn't disappointed. It's the one I shoot best now.
