Go with Qantas - depending on the time of the flight, you will get a really nice meal, dedicated flight attendants and good inflight entertainment.
ON my last SYD>PER flight I was pre-allocated a bulkhead row right in the middle row of three up the front of a 767-300: an excellent seat as I could stretch out and even poke my toes into business class.
I concur that DJ IS a painful airline to fly, and found my last flight BNE>CNS to be the worst experience yet.
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NW Worldperks Gold, SPG Gold