In J, I would pick AA over QF. I find the QF J seats a little cramped. AA seat in an off itself on a flight as long as this makes the case for AA. I've heard (but not had the opportunity to experience) that the soft product on AA on this flight has been upgraded.
Slightly OT, but if you were flying F, I'd say pick QF - no second thoughts about that. The seats are comparable, but the service and food in QF in F is absolutely outstanding.