I have flown on Delta JFK to Athens in both coach and business and believe me, the latter is preferable to the former. The flight over to Athens (or the nearly equivalent distance to Istanbul) ranges around 9 hours, but the flight back is between 10 and 11 and this can get quite long (and these flights seem to be packed--esp since DL doesn't fly to IST or ATH on a daily basis). For me, the overnight flight in coach is the worst but, of course, if you opt for a stopover, in either direction, then at least on the flight out of JFK, say to Amsterdam, you will still have a 7 hour coach flight overnight, then the stopover, and then another 2 hour flight to either Istanbul or Athens. That too can be taxing.
I will say that have found the coach service to be the sort of basic coach service that one might expect, though many of the Delta crews to Athens are, in my experience, most pleasant, helpful, and efficient. If you do fly coach try to get the exit row seats in, I believe aisle 21(check
www.seatguru.com). One of theses aisles has some extra room and the normal seat recline; another exit row has room but no seat recline.
[This message has been edited by heathe (edited Jan 30, 2004).]