About Hong Kong to Shanghai roundtrip, DragonAir (KA) operates about three roundtrips per day. Two on A330s with first and economy class, and one on A321 with business and economy class. It is part of the oneworld, if you want any AA miles. For China Eastern, it operates more frequencies and it uses A340s (two class) and A300-600R(two class), and MD-11 (two class). The two class or three class systems are a bit mixed up here.

Personally, KA has very good service. For Y class, you can expect a hot meal at all times on SHA to HKG route. For F class, you get the trolley service, but the seat is not that comfortable. It is sort the old style CX C class seat with forty five inches of legroom, but the meal is more F class style. For C class on A320/321, it has the typical US domestic F class seat with forty inches of legroom. The meal service is more tray, rather than trolley. All three classes get a menu card for all those flights.

China Eastern... unknown. Some aircraft has sleeper seats... and some don't...

Carfield