The apartment is very spacious and comfortable, and is sparsely but tastefully decorated. It is well-located, with the Hofburg being around a 15 minute-walk away and the Rathaus about 10 minutes walk. The Schottentor U-bahn station and tram stops are very close by providing easy access to the wider city. There are a number of good restaurants (traditional and modern takes on Austrian cuisine as well as a very good tapas place) within a short walk.
We arrived a couple of hours before the check-in time and were allowed to leave our bags in the apartment whilst it was cleaned. An excellent cafe nearby was suggested to us for lunch and by the time we had returned to the building the apartment was ready.
The first evening, we found the apartment to be extremely warm but the house manual was very clear that we should not adjust the radiator valves but use the central heating control. We could not find this unit and, after repeated searching, contacted Anna and Vladan by text only to learn that there was no central device and that we should adjust the radiator valves. Once we knew to do this, we were able to make the apartment comfortable.
We thoroughly enjoyed our stay and would look to use the apartment again if (when) we return to Vienna.