Me and my girlfriend we stayed in Christian's room for 3 nights. We didn't meet Christian in person, but communication via mail and Whatsapp was friendly and super easy. The flat is close to the center and easily accessible by tram, so for us a perfect spot from which to explore the city and get around. The room was very spacious and clean. There are three roommates who are very friendly and open-minded and who are happy to help you out with recommendations when asked. All in all, it's a pretty relaxed and laid-back atmosphere. One night when we returned we sat together in the living-room and watched a movie together. If you're not into that, however, you can always have your privacy in your room. In total, we had a great time and if Zürich wasn't one of the most expensive places in the world, we would definitely return and stay at Christian's place again ;-)