We stayed in Di's apartment for 3 nights, and had a lovely time! The apartment is spacious, kitchen is new, washing machine and dryer, perfect size for the 3 of us. There is netflix on tv, which we liked a lot, movie night with our 10 year old, she picked the movies!
It is an old building, so some noise travels, and you are in the city so you hear traffic also but not that it bothered us a lot (we are used to birds in the morning).
I didn't see airco, so it may be hot in summer and cold in winter nights.
The location of the apartment is really good, with museum station a short stroll away, and buses right at the end of the street. Surry hill a 10min walk with nice eateries (book ahead or eat early if you want a table - as in most restaurants in Sydney).
Di is a friendly guy, lives just next door so he was around if we needed him.
We would book again.