Let me begin with the good - it's 2 doors down from the train station, right next to a liquor store (NOT one with vagrants hanging around it), and in a very walkable neighborhood. It has great views, a nice deck, strong water pressure, quick hot water, and a very comfortable bed.
The bad - the biggest issue is the complete lack of air movement. We were there in March, and it was a high of 94 degrees Fahrenheit one day. While the listing says there is no air conditioning, it fails to mention that windows are locked, and can only be opened ~3 inches (think the size of a small kitten). That leaves the doors, and sliding doors out onto the deck, as the only way to get air movement. We opened everything as much as we could, and though that did cool it down a bit, it was still very, very warm and humid. What was worse, however, is that there are no screen doors or screens on the window. So, my wife and I got tens of mosquito bites each night.
Because the unit is managed by AirbNb, there was no interaction with "Stacey," the owner. As such, when we first got there and asked about where the keys were for the window locks, it took AirbNb 24 hours to get an answer back to us. The answer was that they are locked per building requirements (though we were told by someone else it was per the law. Also, the window over the sink is unlocked, so I'm not sure what the truth is about the locks being required). Bottom line, it was hot and humid, and the only way to make it slightly better was to invite swarms of mosquitos into the unit.
AirbNb, being the manager, deferred totally to Stacey, who felt that because the listing says there is no A/C, that we should have expected all of this. While I knew about there not being air, I think it was a reasonable assumption on my part that the windows would be fully functional and screened (since the listing does not state anything to the contrary). However, because Stacey didn't see an issue with it, AirbNb took her side (presumably to keep her business as manager of the unit), though they claimed they appreciated, and empathized with, our situation.
Because we'd spent a considerable amount of money to stay there, we did not relocate. However, a king sized 5 star hotel room WITH air conditioning and other amenities in a better location, would have been less had we booked it during that time. The bottom line is, unless you are going when you don't need air movement and/or mosquitos are no longer around, I think you have many better options than this place in Sydney.