Sonja's place was fantastic. I could really relax after a long day of walking around Berlin. There is a lot of space and privacy. She also provides some snacks and drinks, which was much appreciated. The apartment is a short walk away (~10 min.) from the U-Bahn stop. From there it doesn't take long to get to the central part of Berlin. There are also some great bars and restaurants about a 10 min. walk from the apartment. I would definitely recommend staying here!