The location is great! You’re right next to U-bahn and there are grocery stores on the block (including the ground floor of the apartment building) if you want to buy food to prepare in the apartment.
It’s an easy walk to the center city and many museums, cafes, etc. We enjoyed the quiet of the apartment, as it is over an interior courtyard and not a busy street.
Cristina was very responsive and a friendly host. I would have rated this higher except the heat was not working for a few days. That said, Cristina provided an electric space heater for the bedroom and fixed the heat while we were there (over a holiday).
This is a pleasant place to rest during your Vienna stay.