The one time I flew CA, it was the 3 hour PEK-HKG flight on CA's A330 in Domestic First/Business earlier this year.

Really good 80" pitch lie flat seating and decent AVOD selection on the 15.4" screens.

Unfortunately the food was meh at best and to top it off, I found a strand of hair in my entree, a first in my many years flying.

The stewardesses were polite and friendly on that flight but their English skill level was very mediocre, having a extremely tough time communicating with the English only speaking passengers sitting around me. Luckily I speak Chinese which made communicating much easier and had some nice chats with one friendly (and attractive!) stewardess during the flight.

Sounds like Shenzhen isn't a horrible step down from CA then... worth a try assuming CA doesn't open up anymore award space in F on their A330 PEK-SZX-PEK flight with the same convenient timing as Shenzhen.