This is a difficult one, partly because we can't trust our memories (nostalgia isn't what it used to be, is it?).
One thing's for sure, though - ultra longhaul nonstops have made economy class long distance travel a pretty awful experience for a great many people. No wonder Singapore has no economy on its longest flights (correct me if I'm wrong).
On the other hand, I remember BA First Class was no better than the first Club (the cradle seats, remember?) and when forty years ago all passengers had their suitcases opened on entry to the US.
The numbers travelling then were, of course, much lower - even a full VC10 arriving at Boston or Chicago will have delivered fewer than 140 arrivals. Now we have the A380.....
P.S. Getting to many airports has improved. Who remembers the rigmarole of getting the A1 bus from Hounslow West, where the Piccadilly Line used to terminate?!