i don't know about the metal ones, i just know about the little vinyl/rubber things that came with my speakers. i never tried them as for a while they were on an area rug. not that i've moved them back onto the hardwood, i'm at the point where i don't care about the floors in my rental which are scratched enough that i haven't tried the vinyl discs out. however, i also don't slide the speakers if i need to move em, i grab hold and lift em (which ain't all that easy) so the floor hasn't really shown ill effects.