I am the son of a 3+million miler and flying colonel on Delta. I had the privilege of growing up flying a lot and I have experienced the old Delta.
I'd start off by saying the old Delta had a way of making the customer feel like we were doing them a favor by giving them our business not the other way around. They had a way of making us feel special: case in point the flying colonel program.
Other old Delta highlights include:
-Red Coats/ above and beyond customer service
-When a wrongdoing or inconvenience was committed against a customer compensation was given by a measure far exceeding the value of what was lost. Nowadays your lucky to come close to breaking even there.
-Complimentary decks of cards given on domestic flights upon request. (Can't tell you how many decks of delta cards we had in the house growing up)
-Complimentary individual bottles of Baileys in first on domestic flights. (After my dad came back from a business trip he'd come with 5-6 bottles, we had a cabinet full of those little bottles. FA's gave away like candy.
-Others have mentioned holding planes to wait for a late passenger. I remember flying with my dad and this occured not because of a connecting flight, but because we were simply late getting to the airport in traffic.
-International fc to die for. The tri-stars were a dream. Huge leather seats two people could almost fit in, fa's were like personal concierges. The complimentary leather toiletry kit, was more stocked than my bathroom at home. Flowing champagne, caviar...the works.
I could go on and on. Bottom line, we were Customers, now we are passengers being hurled on their rig from one place to the next.