A search using both carriers' websites, inputting the same dates for a fare Sydney to London and back, actually shows that QF are approximately $100-150 cheaper than EK. Not taking into acount FF programs, sales, special promotions etc. The next cheapest QF fare was a bit of a hike from the one I found (QF approx AUD1,900, EK approx AUD2, 100
Make of that what you will.
I know which one gives more 'value' in the ticket...
BTW, the QF fare is 1 stop, EK, 2 stops.