Harry's apartment is spacious and clean. The location is close to the main train station and yet the neighborhood is very quiet. We, six members of a family plus a baby, enjoyed there for four nights.
While staying by others, of course, is not as comfortable as at own home, I was impressed that Harry tried his best to satisfy us whenever I requested something. (We were not easy guests.)
Recommended to those who want to stay in Vienna near any public transportation in a clean and nice apartment which is taken care of a responsive owner.