Christiana and Marius were great hosts, communication was effortless and everything around checking in or out was extremely easy and organised. We had a small problem with the water heater during the stay and Marius arrived within 30 mins on a Saturday to fix it.
The apartment itself was good, clean and reasonably well-equipped. It's situated on the first floor of a cosy, closed courtyard which all the windows are facing, so there's very little direct sunlight (at least during this early springtime). Since it's not facing the street, it's extremely quiet all times of the day. The neighbourhood is very nice, some distance away from the most crowded areas of the city, but with many shops and restaurants around and a local feeling to it.
The apartment is conveniently located close to public transportation with a tram stop just opposite the street making a trip to the centre of Vienna within 15-20 minutes possible. The Westbahnhof near-by also make it easy to connect to trains to other parts of Austria and beyond as well as the airport.
Overall it was efficient, easy and I would definitely come back.