I stayed there for 2 months while on a working trip.
The flat was spacious enough for me, but could easily welcome a couple as well.
It's really in the heart of CBD and a couple of streets away from the shopping area. Also, a few minutes away from Darling Harbour and its nice restaurants and views.
Well equipped and didn't have a problem with appliances.
The building is quiet and proper, only the elevator makes some noises.
If you are lucky enough, you might wake up and find cockatoos and/or lorikeets resting on the balcony!