Oneworldplus2 - they take the boarding passes off you because there're no flight announcements in the CL. When your flight is ready for you to board (once on Final Call) they come over to you, give you back your boarding pass and let you know to head down to the gate. It's so you're not constantly checking your watch while you're in there. Sometimes they've brought back new boarding passes with different (better) seats on them.
You can check-in in the CL as well, so you can also just hand over your CL card, and they bring it over to you with your BP once your flight's ready for departure.
As for what's inside - Sydney and Melbourne are both pretty big, probably 100 seats in each. There are about 20 computer desks in Sydney, perhaps 10 in MEL. There's a reasonable library on the back wall at SYD, with a few reference books as well as coffee-table type books.
The food selection at both lounges is relatively small (I'm afraid I can't compare to any of the QPs because I'm only an NB myself, so the only lounge I visit is the CL when travelling with the folks). It's very nice food though. Portuguese[FONT="][/FONT] tarts, miniature pies, smoked salmon, capers, some cold meat, that kind of thing. Usually a soup as well. It's kept well stocked though - if something runs out it's replaced pretty quickly.
In terms of functionality as a lounge, I doubt it's that much better than a QP, or a J Lounge. What's nice is the quietness and the space. You can always find a seat, the TV's volume is low, and nobody's creating a big racket anywhere.
The real tangible benefit of the CL (setting aside the exclusivity that some people appreciate) in my view is the assistance from QF. Any seat you want, the odd upgrade, and you can seemingly switch to an earlier flight no matter your fare class*. I once flew SYD-BNE with my father, both booked on red-edeals. We walked into the CL and they said "The previous flight to yours is leaving now, would you like to see if there's space on it?" There were two spare seats, one in J, one in Y. So they bumped Dad to J and I got the spare Y seat.
When flying internationally, they call you 24 hours from departure, ask you what seats you'd like, and check you in. They keep your passport details on file. They give you the number for the kerbside porter to come and collect your bags when you arrive at Departures.
* I'm not saying this is policy or that it happens every time, but it does happen.
Dad says he gets op-ups about one every 6 flights (majority of his flying is domestic and TT, almost all Y). They're a bit more frequent than that on SYD-PER and TT runs though. Op-ups apparently weren't that infrequent when he was a WP though; he says the increase hasn't been that marked.