If your flights are Tue, Thur, Sat, Sun, the QF Int QP at BNE closes at 00.15am.
Other days, its at 23.30.
Hopefully your day of dep from BNE is on a Tue/Thur/Sat/Sun...
I have not as yet used any EK lounges, so can't compare them with the QP though, but the EK lounge can't be as bad as the VA Per Dom lounge... no views to the outside because of the opaque covering all windows!
I do like the QP lounge at BNE, its higher up, and good runway views.
If they usher you to the EK lounge, all the better, eh?