Tobias was very communicative and helpful before and during our stay. The apartment is good but it had some minor flaws. Also, it will take you about 15-20 minutes by bus/train to almost all tourist sites like Opera House, Darling Harbour, Circular Quay, etc.
Good:
Walking distance from Kings Cross station. Bus stop is also right outside the apartment.
Lots of restaurants, cafes and pubs around.
The room is neat and clean, as shown in the photos.

Bad:
The building is old, so no elevator. You'll have to tow your luggage to the second floor.
Bathroom sink has two separate taps for hot and cold water, which doesn't really help.
There was no microwave oven.