To me, it's similar to midgain on the mid/harm switch. Adds hairy fuzz. I could get used to it for leads, but not so sure for metallirythym. But I like it off for leads too. AND I don't use v30s exclusively anymore, so it's twice as warm and punchy as I had it before, but since I go higher on treble and presence, it's crunchier too in different places.