The Prestige was a good cheap rear derailleur. The competition in the early 70's were the Huret Alavit and Shimano eagle, and the biggest pos that ever existed, the Campagnolo valentino. None were any better. In the fronts, the simplex was a nightmare, that push rod got stuck at the first sign of dust. The Suntour slant parallelogram rear was a game changer like few other cycling innovations.