If you can get one, there are sometimes 4 seats (2 rows of 2) next to the galley, maybe 17 and 18A and B? 19 and 20?, which are slightly more comfortable and feel like your own little minicabin. They are the crew rest seats, so I don't know on which flights they are available. I've only had them coming from JFK.
I generally avoid 78/79 if possible so I'm not as familiar with those as the other numbers. I've probably used them twice in the last three years. It's not intolerable, the Y seats are slightly older and therefore have the extra inch of shoulder space and a thicker cushion under the bum.
Lots of Americans love to hear British accents. Ham it up when you check into the lounges at DFW, you might get an extra chit or two. With my yank accent, I only ever get one, despite travelling with my family of emeralds and sapphires. But I've lived in Britain long enough I don't put up much of a fight
