SYD-JFK on QF is considerably shorter travel time than any of the other routings (up to a day shorter). So there really is no comparison in terms of business travel. If your time has no value and you just want "best J", the answer is still QF esp. if you snag one of the A380 flights that QF will have later this year. From NRT AA F is roughly comparable to CX J via HKG, and no better. JL F NRT-JFK can be quite nice (not sure if all of their flights have been converted to the new F by now). But for DONEx travel I think QF SYD-JFK is the best choice; good luck getting D inventory though, esp. at month end or quarter end or even on peak days of the week.