Excellent apartment, huge bathroom (huge apartment, too), comfortable bed, and spotless. Great location, close to some very good restaurants and a 7 minute walk to the subway. Christl met me at the apartment on the day I arrived and was easy to get in touch with throughout the month. Wifi signal was shared with another apartment. It's up three flights of stairs and no elevator, which might cause problems for people with mobility issues.
Would happily stay there again the next time I'm in Berlin.