At the risk of getting flamed...
A former colleage of mine, who had been Chief Pilot for an operator of both Viscounts and One-Elevens, told me once that the Viscount was an absolute dog of an aeroplane, kept aloft only by the excellence of its engines, and the 1-11 was the most over-engineered airliner in history, indestructable but as a result economically uncompetitive.