I really enjoyed my stay with Karen. She is a very friendly, accomodating host. I felt very comfortable in her home and I highly recommend her place. The neighbourhood (Zehlendorf) is a peaceful, quiet area. However the location is very close to public transport and there were no issues getting to the city center or to any tourist spots. It is also close to Potsdam which was a big benefit. A very nice stay in Berlin and with Karen!