I prefer CX F over QF.
QF is not bad at all, but the seats are smaller (14 in the nose of the 747 vs. 12 on CX), the food on CX (i love asian food) is better and the service is less consistent than on CX.

I would not go this far as taking a connection on CX vs. a non stop on QF, but when i plan my trips i try to optimize them for CX use.