I stayed for 10days at this apartment and it was a pleasant stay.
The apartment was walking distance to pretty much everything;
3-5mins walk to Darling Harbour, 10mins walk to China Town, and if don't mind walking 15-20mins walk to circular quay. If you DO mind walking, there's a bus stop right outside the building that takes you to center of the city and to circular quay.
The apartment itself was pretty nice as well. It wasn't hotel clean but clean enough and was well equipped, except for hair dryer.
Tom was very nice and very responsive.
This was my first time with airbnb and overall I was very pleased with my experience. I'd use airbnb again and would definitely recommend Tom's apartment! and also Sydney! :)