Hi,
I'm using Tria Beauty. It hurts even on the lowest setting when used on face. Anywhere else, it usually doesn't. I just feel a warm sensation. Have been using it for a couple months and seeing less growth already, so yaaay for me! It also sometimes hurts when doing armpits, I think it depends on how clean I shave before. So in the end- if you feel warmth, it probably works ☺