While my overall flight experience was okay, I was horrified that two first-class passengers were able to go the whole flight without a mask. The flight attendants engaged with them multiple times, walked past them to collect garbage, and even let them deplane sans mask! Also, just FYI: upgrading to premium economy no longer comes with complementary wine/beer--a waste of money. I was told this was to limit credit card/machine interaction (which makes sense, more germs), but in premium economy, you don't have to pay for beverages anyway...
United DID listen to my concern but only when I tweeted a photo of the first-class passengers without masks. They offered me a small credit, but in reality, I just wish they would reassure me that mask-wearing will be enforced on ALL flights in ALL tiers.