Katharina and Peter are certainly well-organized hosts. Well before our trip, Katharina was always quick to respond to any questions. The flexible check in/check out times were really nice. We took a red-eye flight and were able to check in right away (quite unlike most hotels in the area where rooms wouldn't be available until the afternoon). The apartment was exactly as described - beautiful, modern, and clean! The neighbors are very quiet and you barely hear much of the surrounding noise (amazing since the apartment is located near a major city artery. The location was perfect - 2 minute walk to the train station, which offers several shops, places to eat, and a grocery store. We highly recommend this place to anyone wishing to visit Vienna and feel like a local.