Want some real heresy? Forget all the Sheratons and W's and Westins, etc. Go directly to the Four Points. (And feel free to pass "GO" as many times as you like, collecting $200 many times over in room rate savings.)
Two weeks ago I spent a weekend at the Sheraton on the Park, and it was fine. I was very happy with everything.
Last week I spent 7 days at the Four Points on Darling Harbour. It was fantastic!
Particularly as this is a leisure vacation, you can't do better. I considered the W as I was working around the corner at Garden Island, but did find the area rather noisy and busy. The Four Points on the other hand was quiet, had all the facilities I needed, was close to the Monorail, an Explorer bus stop, a zillion water taxis and tours, and pretty much every tourist interest imaginable.
For a tourist, "on vacation", this is the ONLY SPG choice.
BTW, if you have a few points, you can stay there for 1600 points + $30USD per night.