This is a lovely place. The apartment building feels very secure, which was important for me as a young traveler. It is not in the city center, but you can easily access the U1 subway line in a two or three minute walk (well lit at night). Everything was very clean and as described and the hosts were very responsive. I would highly recommend this for an urban trip to Vienna if you don't mind getting to know the subway (which is part of the experience!!)