We recently flew LHR - SYD via PVG in CW - one leg on BA and one leg on Qantas each way. BA was acceptable - didn't wow but perfectly acceptable. Very good at topping up drinks etc.
Qantas was excellent. I hadn't flown Qantas biz for 10 years and the difference was night and day to both the previous experience and BA. The hard product seemed new and was very well laid out with good storage, and the seats had a massage function built in :-) The food was excellent, great wines which were well presented and the staff were faultless.
The Qantas lounges are also excellent both in Sydney and LHR.