I stayed here with my wife and young daughter. It's a very nice apartment with great thought into the decorating and attention to detail. The apartment is very modern and much bigger than expected. The photos dont do it justice. It's ideal for a family or two couples. We found it to be very comfortable and had nice homely feel. It has a nice and functional kitchen which we found very useful when traveling with a young child.
We arrived early and were grateful to have been helped by the host's brother Yves who arranged for our bags to be kept safely in the apartment whilst it was being cleaned.
The location was ideal for us. Easy walk to zoo, aquarium, kids parks and supermarket. The bus to airport is a short walk (109 bus) and all other public transport easily walkable. Lots of nice looking places to eat in immediate vicinity . If you are into shopping it super convenient to major shopping strip.
It is on the corner of a main road and not too far from rail but the sound (and temperaure) insulation is fantastic. We did not find the sound intrusive at all but if you are super sensitive you might notice the louder vehicles and occasional train.
Overall a great apartment and so much better value than comparable hotel room. We would definitely stay again and recommend if in Berlin.