Jonny's apartment is in a terrific location. We rode the CAT train from the airport and walked to the apartment from the train station, very easy. The area is so vibrant with shops, cafes, restaurants. Many of the historic sites are walking distance. There are several grocery stores very nearby as well. We felt very safe walking the neighborhood, even at night.
The apartment is clean, spacious and well appointed. It is just as described. Jonny is an excellent host. He was very responsive and accommodating. I would recommend staying here while in Vienna!