It may be out of the centre of the city, but it is on a main tram route with very frequent service, or across the street from a "subway" station that zips you into Flanders St RR station, so getting into the heart of things is a breeze and cheap if you don't want to walk. One of the trams will drop you at the airport shuttle at Spencer Street RR station.
As a GOLD, I usually get well treated and upgraded, but on my last stay, I had to request benefits from a very poor reception clerk. Given Melbourne's costly high end hotels -- Sheraton, Hyatt, Westin -- the Hilton can be a good value if you don't mind being on the edge of the city.