I've just gotten a folder with twist shifter, my first experience using twist shifter. I've used friction shifter (on a racer) & index trigger shifter (mountain bike). At first, I didn't like it but then after a few more km, I've gotten used to it & found it quite good & fast shifting for road use. Doesn't slip on my sweaty hands yet. Hope they last.

All 3 works for me. More expensive folders I've seen come with index shift though