I once had a conversation with an ex BEA Argosy and Merchantmen caption who told tales of flying the -100 series Argosies which didn't go too well, especially if leaving Turin, they had to circle while climbing before crossing the Alps, then the more powerful -222 version arrived which was a big improvement. Until BEA decided the Viscounts had a greater need for the more powerful engines so they did a swop and the Argosies went back to struggling again. Might have been just a pub story though.