Luckily about 8.5 years ago, I got to work in Aus (Perth) for a few weeks, making 2 round trips in total. The company I worked for at the time had a contract policy that coz it was Perth, i.e. Western Aus, it was economy only for business travel. If I had gone with them to Syndey, as a colleague did, it would be business class default coz of the extra journey time.
However, I bucked the trent for Perth, buy my height

I'm 6'7", and went to see one of the directors at the time, and he signed it off for me going business class.
So had 2 trips, one with Quantas, one with Malaysian. Must admit, Malaysian was better, food, seats, and amenities (TV and video and that in flight, and lounges at airports). The lounge at Kuala Lumpar airport is amazing, absolutely huge
Anyway, I learnt from this, for a distance like that, Business Class was the only choice for me. So 2 year later, I went back there on hols, and paid about £2500 for business class, with Malaysian. And in terms of 24 hours in a planes, I am glad I did it