I would also recommend taking the CX nonstop in J vs. AA F->NRT-CX J->HKG even though I am not a huge fan of the NBC J seats on the Airbii. The flight schedule is extremely convenient and food/beverage/service/IFE will be very good.

One other drawback to going via NRT is that several of CX's NRT-HKG flights are on "regional" equipment where the J seats are only marginally better than AA/UA domestic F seats; and it's a 5+ hour flight. I believe only the 744-operated flights on that route have 3 cabin service with international-style J cabins. Of course, the inflight service, meals, etc. are still excellent even in regional J.