I got so tired of messing with the balky RapidFire thumb shifter on my mountain bike I switched to a cheap Sunrace friction thumbie a month ago. Works great, no more chain rub on the triple.

Only a bit less convenient, but good enough. Still keeping the RapidFire thumbie for the rear derailer. Works fine, and quick RD shifts are more important for my riding.

I like it so well I'm going to swap out the RevoShift twisty grip on the other bike's front derailer for another Sunrace friction thumbie. Never could dial out the chain rub on that bike. But as with the mountain bike I'm keeping the original RevoShift for the rear derailer since it works fine.