Vis a vis crowds, and how to get them through the gates. I can't comment on Melbourne because I've never been there, and my knowledge of Sydney is limited, but I can comment on SEQ, which is the only place I've ever been to the footy. I've been to 5 different grounds - Seagulls, Carrara, Robina, QEII, and Lang Park (only since the RWC upgrade). Add in the Gabba for a few AFL games (and cricket). Lang Park in its current guise is absolutely brilliant - wonderful stadium, purpose built for League/Union/Football ($500 mil will do that), awesome atmosphere, not a bad seat in the joint. I have a similar opinion of the Gabba (which also had a truckload spent on upgrades for the 2000 Olympic Football), and Robina is basically a minature version of Lang Park. Carrara is/was crap in every way, though I'm guessing something will be done for the new AFL club. Seagulls is long gone, but was a great place to watch footy. QEII is/was nearly as crap as Carrara.
When you look at all 3 main stadiums in SEQ, you can see why they draw such good crowds. Loads of governent money poured into building/upgrading all of them. Very good (and free, by the by) public transport (two next to train stations, the other with a bus interchange across the road). No parking at any of them, but the free public transport makes up for it (or makes it better by avoiding traffic jams). All 3 of them all-seater, fully enclosed stadiums designed to place the fans on top of the action no matter where they sit. Ticket prices are higher than Sydney as far as I'm aware(someone has to pay for the stadiums), but when you factor in the free transport and how good the stadiums are, it's probably worth it.
So on top of the natural advantage the Broncos, Titans, Lions, GCU, Roar, and Reds have in being the only team in town in their respective codes, they have excellent stadiums which are easy to get to and from, which makes it more likely that some umming and ahhing between going to the footy or watching on telly will take the former option.
One more minor point - SEQ's bus and train networks are integrated into a single public transport system. Has Sydney managed to enter the 21st century in this regard yet? It hadn't last time I was there (2005).
