Christian is a very kind host. He made sure that I was comfortable at his place. He gave me many useful tips on exploring Vienna. His appointment is very clean and quiet, and the location is very good. The tram stop is less than 5 minutes walk away, and from there one can take either of the two trams to city centre and connect to other trams, buses or subway. I definitely recommend this place to travellers who are responsible and respectful.
Christian, thanks again for the good stay!