Earlier this month I could expericence the Delta transatlantic product myself:
Both legs were operated by 763's and I found the service to be very basic. The only touch of class are the little menu cards distributed by the crew.
The meals were edible - but if they make the trays any smaller, you would need magnifiying glasses to be able to detect them.
On the flight to NYC, the cabin was looking very tired, it wasn't too clean either. Some parts very clearly hadn't seen a wet cloth for ages. The New York based cabin crew was friendly, but not overly interested in providing service. After lunch, the entire crew disappeared (even in Biz Elite ... I had an exit row seat so I could overlook most of the Elite section, too), they reappeared for a quick round of drinks, disappeared and came back for the snack service shortly before landing. To call them unfriendly or even rude would be a lie, they just did nothing whatsoever to make this flight a memorable one. They were very stingy, even with their smiles.
The return flight was more pleasant, thanks to a very cheerful Cincy-based cabin crew (the fact that I had another exit row seat also helped). However, the cabin was very tatty. The monitors didn't work properly (so major parts of the safety demo on video wasn't visible, just audible). One overhead bin just wouldn't close. What worked, however, were the call chimes in the galley. They were so loud they would even wake up the dead. After landing the chimes wouldn't stop at all, much to the annoyance of the passengers (the crew didn't seem to notice, obviously it wasn't the first time this happened!).
All in all, one can see very clearly, that Delta has run out of money. Poverty looks at you all over the place. It's a shame.
Memorable flying to all of us.