We had a wonderful stay at Karsten's place, flat is exactly as in photos, very stylish and lots of nice decorative elements. As from practical view it's a seconds away from U bahn station that means you are minutes away from musums center and from any other district in berlin. Berlin Wall is on walkable distance, about 10 mins.
Karsten himself was a great help, he shared his advice regarding sights, how to get there and even signed all places on map! We carried this map with us during all our stay there.
Neighborhood is very quiet and nearby is a park to breath fresh air and a grocery store. Definitely recommended to stay here and hope to come back again!
Thanks.