3 years ago, CX J would be a clear advantage. Now, not so much.

Food: CX is marginally better. Panda Express reheated week old food is still better than what CX is serving.
I just skip AA food most of the time.

Service: about the same now. Really sad because CX used to be very good.

Hard product: AA is slightly better.

Just go with one with better time or one that gives you more miles.