But not much longer in total.

Douglas Sleeper Transport could have cruised at, say, 275 km/h and thus taken 6 hours to fly 1650 km (while a modern jet does it in 2 hours), but it would then have flown 6 hours in total, and most widebodies can fly longer. Transatlantic flight may have taken 15 hours by propliner and just 6-9 hours by jet, but surely there are jets, like B747-400, A340 or B77-300ER, which can fly 15 hours and more at a time, while getting much further than transatlantic, with less noise and turbulence. So what is the service like in a 777-300ER?