We stayed in Birgit's apartment for 1+ weeks. The apartment can be reached with the subway U1. It is located in an old apartment block that is equipped with an elevator. The main room is quiet when the windows are closed and the heating works well. There also is a kitchen with several amenities (stove with two plates, water cooker, microwave, etc.) and a bathroom with shower and toilet.
Birigit was a forthcoming and helpful host who responded to our messages right aways. Thanks!