This is a good apartment in a great location. Rainer was a hospitable host, meeting us early to allow us to drop off our bags before check in and showed us the ropes, he also allowed us to hold the bags in the apartment until we departed later in the afternoon which made sight seeing much easier for the day.
The apartment itself was comfortable and a good size for our family of five. It is close to Alexanderplatz station which provided us easy access to all of the sites in Berlin that we wished to visit.