"I am HH Gold and SGP Gold. Does the Hilton Adelaide have a lounge, upgraded rooms? I am not sure to which hotels in SYD or MEL to look at."
The Hilton in Adelaide does have a lounge with a free drink in the evening from 5pm plus snacks from 5:30 - 7:30. The executive rooms are quite nice.
In Melbourne, the hotel I would recommend is the Grand Hotel which is located on Spencer Street at the corner with Flinders Street. An excellent hotel. I spent a year living there in one of the 2 bedroom apartments and wouldn't hesitate to recommend it to anyone.
Dave