A few years ago it seemed time to replace my trusty pig-nose purge valve face mask. And i decided to get two, and different brands at an expensive Silicon Valley dive shop, so that i would always have a good spare.
Even got lens put in for my nearsightedness and astigmatism as i wanted to see what difference it would make. Bought 2 black cases, and even suckered for the bottles of anti-fog ,tho i always use and prefer good old spit.
After only a year of skin diving in Hawaii and Mexico and always , always, rinsing off with clean water and drying in the shade the two masks,,,I noticed the Scubapro mask's silicon skirt was getting quite YELLOW.
So i attended the local penultimate annual dive sale in Redwood City and asked the rep for Scubapro if they would replace the obvious by comparison much yellower Scubapro mask skirt. That would be a "no".
From now on , I am only buying U.S. Divers masks.