The 777 seats on QR are good but not as good as CX J seats. However, if you are flying with your wife maybe 2-2-2 is a better configuration?
Also consider the flight times. Personally I would prefer a short SGN-HKG connection followed by an ultra long haul to the US, and QR do like to schedule weird and wonderful stopovers in the middle of the night.
All things considered though, both are still amongst the best airlines out there. For half the price i'd be going on QR.