Which Premium Economy is better VS, BA or CX, QF is to dear, and I hear the Chinese PE is just Economy.

China Southern has one of the best business class products on the A380. It's a Chinese airline. Surely you're not expecting staggered flat in Y+?

As for the other airlines, China Eastern has a solid angled lie flat product (even though it looks like it's almost 45Ëš from the ground) and Hainan Airlines has good angled flat as well. As for Air China, they're also fully flat. So I don't get what you're trying to express about the inferiority of Chinese airlines.

I flew WT+ some 10 or so years ago. The crew were shocking, ignorate and rude. But they may have changed, or it was my luck to get a bad crew. Can get WT+ for $6780 for two people. not bad.

As mentioned earlier I quite like BA WT+, but this year I will probably do something quite different. You can go JQ business MEL to BKK and then AY (Finnair) BKK to HEL and on to LHR  on either BA or AY all in business for around $5500 depending on time. AY runs quite a good J class, not as good as QF or BA/CX, but very good for the price. And if you go JQ business Max you end up with a lot of status credits. It is of course a bit fiddely and  if you are in a hurry, not much good, but as I am retired it might suit me.

On Finnair, I'd be interested to know how much their combo fares cost (Aus-Asia in Economy, Asia-Europe in Business). Anyone done one?

I have booked my own “combo” with separate tickets to BKK by JQ/QF and to HEL by AY. IMHO this is the best way – BKK-HEL-BKK is only $2.5K in business! In contrast SIN-HEL-SIN is more then $5K and I mind you that they still use sloped seats on SIN route while on BKK they have new excellent business class (if you get ticket on A330). Though there is a problem with combo flight to HEL via BKK. BKK-HEL departures 9am so you have to flight overnight in cattle or sleep over in BKK (I choose sleep over J). Good Luck.

I haven't checked the combo fare, but SYD - HEL  - LHR (SYD/SIN on QF, the booking site won't let you go via BKK) on AY is nearly as much as QF via Dubai in J. To make a good saving you need to position yourself in BKK, that's why I will fly JQ in J to BKK and catch AY from BKK. A complicated way to get to LHR, but I have got lots of time and I get to have few days in BKK and HEL and it will do wonders for my status credits! 

IMHO PE only worth considering if it no more than 50% dearer then economy. And even then I would prefer exit row in economy over “ordinary” seat in PE. Otherwise waste of money – they add some non-essential perks, but seats still economy style with 5mm extra padding and 1 degree extra recline. YMMV.