I went to college in 1986, so I was doing the SJU-BOS-SJU route constantly, it seemed (vacations, long weekends, and the need to get out of what was, for me, an absolutely shocking cold weather -- brrr).
My airline of choice was AA, which back then was flying several flights a day on that route. In Y, seats were more padded than they are now (or who knows, maybe the "freshman 15 made my arse more padded). Either there was more legroom or people have grown a lot taller, because I could easily sit in a window seat, get up to use the facilities, and come back in. These days, even attempting that in some J class configurations is more than I can manage, and I stick to the aisle seat.
Food in Y was airline food -- but it was there and it was hot.
There was no IFE -- just the TVs above the aisles every five rows or so. They would play an edited version of a movie, and if you missed something because the FA spoke to you or because you went to the lav, oh well. They were never great movies, really.
I don't know if the bidding system was different back then, or if some FAs liked working certain routes, but it seemed to me that we often had some of the same FAs on this route, and once they recognized you, they were always warm and friendly -- asked how school was going, brought an extra tea on early morning flights or Diet Coke on later flights unbidden, just because.
During winter break, these flights from BOS-SJU were almost like a school bus taking all of the boricuas home for the holidays, and they could be quite a party. People would be drinking, exchanging home phone numbers (this was before cell phones), and letting one another know who was having parties, where, and on what days. By the time you got off the flight, your winter break was more or less scheduled.