We were in touch in Roman who was very flexible changing our booking due corona restrictions in November. We moved it to February and they adjusted to our days and the check in was smoothy and we truly appreaciate the late check out leaving our belongings in the room until we had to get to the airport.
Easy communication, kind and easy going host, very clean common areas, well located and really good recommendations (we went to 2 of the restaurants that they proposed)
We absolutely recommend to stay in their apartment if you visit Vienna