We stayed in Jonathan's guest suite for a weekend (3 nights), and our stay was very nice. The space was comfortable and clean, and was a very good fit for two people, and would likely fit three people quite nicely as well. The location is a nice and calm neighbourhood. Busses come fairly close, and the S- and U-Bahn are a 15-20min walk away. We usually decided to walk to the S- and U-Bahn stations as they usually offered more direct routes to the places we wanted to visit. Check-in was very flexible, and as we had some problems during our journey to Berlin, it was easy to keep in touch with the host about our changing timetable. Jonathan was not present during our stay, but he organised a friend to meet us for our check-in upon arrival. Overall a very nice accommodation, recommend for a calm and relaxed stay in Berlin. :)