We really enjoyed staying at Studio 22. The location (~1 minute's walk from Kings Cross station) makes it super easy to get around the city, and is near some great nightspots. Even Bondi is a pretty simple 30 minute trip.
The room itself was comfortable and well designed, and gave a great view of the city, stretching out to Sydney Harbour Bridge.
The only possible drawback we can think of is that the lack of air conditioning could be an issue on really hot nights, but there were two fans in the room which were enough to make our stay comfortable.
In all, Romy and Rupert were great hosts and we would definitely be keen to stay at Studio 22 again.