Congrats on your upcoming move SFO777. I think you will feel right at home on the East Side. Your pics of the prewar apartment near Sutton Place reminded me of where I lived as a baby/toddler (1982-85, so I am one of those "effing millennials"
) ) My parents loved the east 50s because they could walk everywhere in midtown with relative ease - shopping, restaurants and their offices. And they paid $750 a month back then, as it was a rent-stabilized illegal sublet
There is also something to be said about the convenience factor of living in Manhattan. Just about anything you want is at your doorstep, within a mile or two, without having to deal with driving or parking your own car. And even though the traffic to JFK is a pain (at rush hour, the E train from 53rd & Lex + AirTrain is faster) you have multiple nonstop options to so many destinations from all three airports.