I just don't get what's the big difference. I've been in both QP & J Lounge in Sydney & Melbourne... both when packed & empty... they seem to be much of a muchness. The food is not great in both, often both have stain ridden couches & they both can contain loud obnoxious bogans (thanks open plan design lovers!).
If you like apple cider then the J lounges in airports where they existed (MEL, SYD, BNE) used to be better, with Bulmers instead of Strongbow available. PER and ADL, which don't have J lounges, had Bulmers anyway, though.
I'm not sure if that will still be the case now, though; the PER QP has recently moved to Five Seeds, which is a shame. I'm hoping this isn't across the board and that Bulmers will still be available in the J lounges when they re open.
mrpooky.