Location is a mininimal as a tiebreaker; the tramway "super" stops work far more efficiently for the PH and as mentioned the train is closer by if you need Spencer St or the docklands (I rarely do taxis/uber/etc.).
However I find the PH generally so far exceeds the GH in stays as a diamond in recogition and related value-add that I would not contemplate a GH stay over a PH stay unless the cost is at least $100 more.
The PH is simply a nicer place for us to stay.