Fuel Efficent
I recall as a FO when flying the 50 series, fuel efficent operation translated into how far can I go today. Summer flying, FCO JFK was always questionable non stop. Often if the decision was made early enough, SNN would get a breif visit, and the pax treated to a nice duty free shopping event. Or if the winds seemed to be more favorable, (rarely were) and if JFK became unable after SNN overfly, BKR would get the pleasure of our drop in. No Goose, No Gander, was still not quite true west bound in the summer.