The problem is most of us can't go to USA just for status run. For anything close to home, QF flights maybe a quick and relative cheap run. Business class to AKL can be had for just over $1000 return and you earn 160 sc. I would pick Emirate operated but QF coded flights to get the best of both world. That is 1.6 sc per $10. Compare to a domestic BNE/SYD/MEL run on economy sale fare, which earns 10 sc one way, you need to have a fare as low as $60 to beat that.
If you need more sc in a short period of time, you can always fly First class for $2500 and get 240sc. Not as good on the sc per dollar though.
Or you can try Jetstar OOL-NRT business max, during sales you should be able to pick it up for $800 one way and pick up 120 sc. That's 1.5 sc per $10.
These options may not be that good compare to the good ole days, but for people who is a bit constraint with time.
For anything abroad, the other good choice is Sri Lankan. They usually offer cheap business class fares. Only problem is, you need to go to Sri Lanka.
For Virgin, the best way is family pooling. One premium economy rt to LAX for a couple on PE, should get you 480 sc which is almost gold. If You have kids, then a typical family of 4 will get you 960 which is almost platinum! Watch out for those happy hour deals. Recently they just did PE rt at $1999.