Originally Posted by
Flying Doctor
Just to concur,
Check in opens around 3 hours before the first flight - they both leave about 11pm.
Qantas Lounge OK.
Cathay Wing much better. I'd go there. Gate 1-4. Come out Security from the side which you will use having checked with BA and turn left and keep going. You need to go down one level unless you have a Gold card with BA. It is a about a 10 minute walk but its the best lounge.
The Pier is near gate 65 which is also good (only business class there - the Wing has a First section).
That is my view. Done it many times!
FD.
Both the Wing and the Pier have business and First lounges, the only Cathay lounge which is only Business is the Deck (which is next to the Qantas lounge).
I'd say the order of the Cathay J Lounges is Pier > Deck > Wing, though if the gate is the near end of the terminal it probably isn't worth going to the Pier (it would be if you were in F/OWE, as the Pier F is one of the best lounges in the world, but Pier J is only marginally better than the other J lounges).
That said, the Qantas lounge is probably the most kid friendly, and given that BA often use the gates next to it and the Deck, that's probably OP's best bet for an easy experience.
Edit: Ah, this OP doesn't have kids, I was confused by the fact that there are 2 very similar threads asking about HKG, the other one had kids. On that basis then, and if the flight is going from a gate near the Pier, I'd definitely go there.