For a J seat, I’m going to be a contrarian here and suggest AA for the seat. Yes, service and food will be much better on JL, but it’s still just reheated airplane food. I flew a JL 777 (the version with no F) SFO-HND last winter and it was probably the most uncomfortable seat I have been in since the angle flat JL 787 they used to fly to SAN. I’m tall so that probably played into it, but the 1-2 hours of better food and booze in no way make up for the 7-8 hours of discomfort for me.