Susanna is a great host, she was very easy to reach.
The apartment is very central (in walking distance to the city center), the street is quiet and safe.
Parking is a bit tricky as it is not possible to park on the street long-term. But Susanna recommended several parking garages in walking distance and offered a partial refund for the parking costs.
Overall we had a great time in Vienna and would recommend Susanna's apartment to anyone.