Christian wasn't home during my stay, but his neighbor was kind enough to welcome me and keep in touch. The apartment is well-located, spacious, and well-equipped. The private room was charming and clean. It is situated in a lovely residential area, with a 5 to 10 minute walk to metro stations, and a variety of supermarkets and restaurants. I especially recommend the cute korean coffee shop Sweet Honey across the street. I will definitely consider staying here again during my next visit to Vienna!