Well, the shortest flight is, without a doubt, the nonstop on CZ. In the past, CZ has used 10-abreast 777s on that route, which are about as comfortable as you're probably imagining. Business class isn't too great either, but isn't nearly as expensive as J on first tier airlines, so that might be worth a look. If it were me, I'd try to get an AA award ticket on CX to/from HKG in one direction and tolerate CZ the other.