My main commuter has downtube friction shifters, moving a chain across an 8-speed cassette. In the winter, I'm wearing various ear covers, which make it pretty impossible to use hearing to know whether I need to trim the shifter or not. But I can feel it in the drivetrain if there's some rubbing on a front or rear derailleur. And I think I've also gotten used to seeing the position of the lever and how much I need to move it in order to shift successfully. Probably wouldn't work if I were in a race, but for my short commute, it's just fine.