First of all, Denise is a very helpful host. Once I alerted her to my presence in Vienna, she called to provide me with the directions to her place. She also waited for me outside the building to guide me to the apartment. The apartment itself was exactly as described in the posting, with all the amenities and equipment that you will need for a small apartment like this. Concerning cleanliness, all of the apartment, including the bathroom, were super clean. As for the cigarette smell that some people mentioned, I did not smell or feel that somebody had been smoking in the apartment.
While parts of Vienna are easily reachable by tram or the U-bahn, the apartment is centrally located in the 1st district, a perfect location if you're planning to go visit the opera house, the kunsthistorisches museum or the Hofburg palace. The apartment is literally 5 minutes away on foot from these monuments! Will definitely come back if I'm ever in Vienna again.