We had a lovely stay in Michael and Mathias's apartment. The location is super, very close to the university and several of the tram and bus lines, and just across from the large Hof (AKH) of the university where Stiegl-Ambulanz and several other wonderful restaurants are.
The apartment was very clean and well appointed for our stay. We had our toddler with us, and they provided both a high chair and a pack-n-play crib with bedding, which was very helpful. Because it was very hot during our stay, they even provided an extra fan, and when one of them broke, they quickly delivered a replacement. Overall they were great at responding to our communication from the reservation through departure. We can highly recommend their place!