Katja’s apartment is very comfortable, modern, spacious (larger than you would expect based on the photos), well equipped and located in a nice neighbourhood. Although train track is close to the apartment building, it’s not annoying at all. Within 700-900m, there are several subway/train stations that can get you anywhere in Berlin. Supermarkets/bakery are at walking distance. Katja was very hospitable.
Highly recommend it!