My brother and I recently stayed at Christoph's apartment, and the experience was really great from start to finish. Christoph was very responsive and helpful with directions, and coordinated to have a friend meet us to give us the keys since he was abroad when we arrived... She even met us again when we accidentally locked ourselves out the next day! The room is very spacious, the bed is comfortable, and the apartment has all the needed essentials. It also is very close to the U6 metro line, and there is a delicious Italian restaurant and very affordable cafe within walking distance. I would definitely recommend for anyone to stay here and would happily stay again.