Clemens's apartment was very comfortable, renovated and very clean. There were amenities like a coffee machine and anything that one would need during the stay. The location is perfect because it's really close to the subway which takes you to the city center in matter of a few minutes.
Clemens was also very punctual, helpful and informative and responded to the messages very fast. Checkin/out process was very simple.
I would definitely recommend it again for staying in Vienna.