The apartment is even nicer than the photos show. It's a new renovation in an old building with large rooms and light but on a quiet pedestrian street. It was very clean and the bed is comfortable. It's minutes from food shops and restaurants, and very close (5-15 minutes walking) to many of the museums and tourist sights.
Ujale was quick to respond to our questions and graciously accomodating to our arrival and departure schedules. He greeted us at the apartment after a delayed flight of several hours and was willing to make arrangements for holding our luggage for a late departure.
We recommend it highly and would stay there again next time in Vienna.