This flat is exactly as described! It was perfect for our family of 4 (myself, husband, 11yo, 9yo). This was our first trip to Berlin (from US); we chose this location specifically because it is very close to where friends of ours live.
The flat is located in a quiet, residential neighborhood. It is a very short walk to the tram station and then about 20-30 minutes into the center of Berlin.
We frequently had breakfast in the flat (grocery nearby) and sometimes dinner. We washed one load of laundry (it took us a few minutes to figure out that the water to the washing machine was turned off where the hose connects to the faucet at the wall, once we turned that on, success!). Wifi was sporadic in the bedroom, but no problems in the kitchen & living area.
If we are fortunate enough to be able to come back to Berlin, we'd absolutely stay here again!