We stayed in the bottom apartment which sleeps 4 people (one bedroom with a king bed and bunk beds). Everything was very modern, new and very tastefully decorated. The kitchen is well-stocked and there's a nice covered patio out the kitchen door, although it was too cold for us to use in March. The only complaint we had about the layout is the bathroom is between the kitchen/living room and bedroom. Therefore, if someone was using the bathroom you were "stranded" in whichever room until they were done. This is not a big deal for a short trip though.
There is a tram stop (Strassenbahn) right out the front door which will connect you to many bus routes or to the S-Bahn in Koepenick, which makes it very easy to get anywhere. There's also a grocery store (Aldi) just across and up the street. There aren't any bakeries or cafe's nearby which was a bit disappointing. We stayed in this area because we wanted to be near family. If you would like to be closer to central Berlin, I would not recommend staying in Koepenick (travel time to central Berlin would be about 30 to 45 min). However, if you are visiting in the summer and would like to spend time on the water and outside, this is an ideal location! We thoroughly enjoyed the apartment.