I've been using the clamp on the left side of the DeWalt 8.5" sliding compound miter saw.  I've been cutting a lot of floor boards (laminate/composite) with it over the past week and the clamp helps keep the stock very steady.  There is a quick-release button that drops the clamping screw down very quickly and this can be done with one hand.  However, loosening it with one hand is more difficult.  You can unscrew the clamp one-handed, but releasing the quick release takes two hands.  On the right hand side, the clamp works for straight cuts, but gets in the way of any cuts with the saw swung to the right (the side that goes to steeper angles).