We had a wonderful time during the seven days at Natalie's house. Her parents were at the house and gave us a lot of tips on how we could spend our time in Sydney. They were very kind and thoughtful (they often asked us if everything was ok, if they could help us in anything... they even offered us to use their bikes if we wanted to)
The house is very clean, the room is a little bit small if you are carrying too many bags, but if it's not the case, then you are fine, and it's pretty close to the city (20-25min by bus, which comes every 3 min).
One thing that I founded pretty cool: the have a small guide that were in our room explaining how to get to the city, what buses you could take, where you could go, where to eat, to buy food, remedies, hospitals... everything. It's really nice.
If you are looking for a warm, cosy, and, cheap place to stay in Sydney, that is the one you should consider.