It's been a while since I flew AA on trans-con, but I can give you some info on United's service. A friend of mine just did Delta and he said it totally sup-par, hated it. AA's got the major upper hand on frequency and capacity.

UA's new p.s. service is geared up to flyers like you, paying full fare. Economy is a total afterthought, claiming a space smaller than the business cabin.

-C is 4 abreast, with new leather seats and very very spacious. Not a bad seat in the house.Sit in row 9, you could park a car in your legroom!
-F has new electonic sleeper seats, akin to most intl carriers business class. -Personal DVD players are distributed with 10 movie titles in F and C.
-Eye shades and socks are distributed in F and C.
-All 3 cabins have in seat power with no need for an adaptor.
-Flights are usually serviced by the amazing JFK based crews.
-Hot food service in Y, with a full range of special meal choices.
-34" of pitch in E+ throughout the cabin.
-UA's T7 at JFK is small and conveinient, with a clean pleasant interior. Always just a short distance from check-in to gate.