The apartment was very nicely decorated and included everything we needed for our travel party of two adults with two small kids. The neighborhood is peaceful and well accessible with the local traffic of trams and metro.
The place is easy to get to from Tegel airport with public transport, even with a child in a stroller. When we arrived, a friend of our hosts met us in the apartment and gave us plentiful advice on different sights and activities for our holiday in Berlin.
I am happy to recommend Katja's apartment to all Berlin visitors!