Barbara's apartment was fantastic. My wife and I stayed in May for 5 nights. The location in the university district (about a block from a U-bahn station) was awesome. Restaurants, museums and small grocery stores in all directions. The apartment itself is in a courtyard
off the street and is very quiet. The kitchen is small but functional. We had no issues with WiFi. The curtain system on the windows is completely 100% blackout, so if you are sensitive to light when sleeping, this is the perfect place for you. We would absolutely stay again.