Hae-ok was very responsive on emails. Her apartment was very clean when we arrived, and had a well-equipped kitchen. The apartment was very spacious for 3 persons (it's big enough to house 6 I believe), and had a great view from high up! In addition, the location at Hackescher Markt was fantastic - many food/drink places and 2 S-Bahn stations within walking distance. Major attractions - Berliner Dom, Bebelplatz, various museums on Museum Island - were nearby which made the location excellent for itinerary planning. Highly recommend.