I love sustain and would never use a foam mute however: I have high mass bridges on basses with less sustain than cheap bridge basses so I don't think it makes as much of a difference as others say it does. I use my right hand to shorten the notes of my choosing, I often mute the strings as the snare hits for space and drama. I play fretless with flats and my right hand gives the sustain or space I need.