It's a beautifully quiet design. If I want to check if someone came back I can, and sometimes I don't have the energy to look. The quality is the effect of all

It's a beautifully quiet design. If I want to check if someone came back I can, and sometimes I don't have the energy to look. The quality is the effect of all these little things, and not something one could affect top down in another design. I suspect there is a ton of sophisticated stuff going on behind the scenes, but even if there were, the effect is still too good to complain about.