It's a very nice lounge, but never designed to be a hop on the kangaroo route.
A couple of weeks ago I got to the airport and into the lounge (after a day spent in the city) just before an A380 of pax (either to or from LHR, don't know) landed. Luckily it meant no waiting for the showers, however the very next pax behind me was handed a beeper. I was able to find space to sit for dinner, however after dinner it was a little more difficult to find space to sit in a comfy chair. I ended up asking if I could sit at a spare chair in a group of 4.
Of course the question does become how long do they continue flying A380's to LHR? Will all LHR flights end up being East Coast-xPER-LHR on B787's? If so then the lounge will again be demoted to destination lounge / Asia hop, so perhaps that's QF's end game.