Stefan was not in the city during our stay but Bohana was cohosting with him and both were very nice.
Bohana was waiting for us in the apartment, she explained were the things are in the appartment, what we can find in the surroundings, and some interesting possible things to do in Vienna.
The apartment itself is as described in the post. The only BUT we found is that these days it was very hot so we have to sleep with the windows opened, what makes the apartment very noisy.