We were very happy with Gregor Konstantin's apartment. Gregor was quite flexible in the time we met him upon arrival, an added bonus. He showed us the place and helped us with our bag. The apartment is on the second level, so there are stairs to climb, which wasn't a problem for us, but something to be aware of. He left us phone numbers to contact him if we needed, and he lives right next door, so easily accessible. The apartment itself is very, very nice. A wonderful location, with plenty of restaurants and shops within a few blocks. The bus and the U-bahn are very close to catch. When you come home after a day of sightseeing, there is no need to take the transit back out, because you can walk to several local places to eat or drink. The complex of apartments is very nice, lots of kids playing and family life. It made our stay in Berlin extra special.