Chain #1: SRAM PC Red22 11 speed on a SRAM cassette. It's the shiny one. Very quiet when clean and lubricated. Replace at approx. 7700 miles and well before 0.5% using my Park chain checker tool.

Chain #2: KMC X11 with the oil slick purple finish. Maybe a couple of hundred miles. Always seems noisy, like a dry chain even when freshly lubed.

Both chains very clean from factory lube and Squirt drip wax after cleaning and as needed.

Are some chains just noisier than others? Which is the quietest? I have an unused Shimano chain so we'll see how goes next time. Some riders swear by Wipperman, although I have not tried that brand.

I will gladly give up longevity for quiet.