The comparison should be to a standard mouse pad imo, not no mouse pad.There's always a few crumbs on my table and it messes me up when it goes under my mouse.
Incidentally, I'm not a fan of the metal pads. Even the smoothest wear out the teflon feet on your mouse at an alarming rate (if you're a heavy user, you'll go through 2-3 sets of feet per year).
Where does one buy these teflon feet for interest sake?
You have to get them through the manufacturer website, generally. I haven't seen a place in SA which stocks them.