Just returning from AU for the first time to pick up my 50K starwood points I checked out a few properties.

Sydney - The Westin is the place it is in the center of the city....wonderful stay huge rooms and bathrooms.

The four points nice on the harbour a short walk across the bridge to the Casino.Nice views. A comfortable place it's just not a luxury hotel.

The W - not a great location very hip,I stayed in a loft room and a little tight on space.I wouldn't go back,because of location and rates.

I then went to the gold coast.If you want to hang out with a crowd your age this looks like the place for you. I mean it has everything.Great beaches,golf,surf,casino and oh yeah bars that go on all night long.
The place to stay Shearton Mirage right on the beach and a true luxury hotel.
E-mail for more info if you would like.