We had a wonderful time at Ralf's place. It is in a very convinient location, between two metro stations, surrounded by many shops, supermarkets, bistros and breakfast places. It is also pretty close to the center, we enjoyed taking the metro and be on a calmer side, which made us feel that we are closer to the locals. I could reach Ralf anytime online and he organized one of his friends to meet us and hand over the keys on the day of our arrival as we had a late checki-in. Would definitely recommend his place in the future and maybe we also come back. :)