True, Coach is not comfortable on a long-haul flight but at least the DC-10 gives you the opportunity to get up and walk around if you need to. Try and get an aisle seat and then take a stroll up and down the two aisles when you need to stretch.
Obviously, you can't move about freely when serving carts are in the aisles. Still, the wide-bodied DC-10 gives you much more freedom that the single-aisle 757 when you need to escape the confines of your Coach seat.