Stefan's apartment is extremely well located near the center and only 5 minutes walk from the nearest metro station, so getting around was very convenient.
The apartment itself is very quiet, spacious and beautifully designed, facing a gorgeous half-wild garden. Central heating was great, and authentic wooden floor and unique furnitures completed the perfect atmosphere. The garden deserves its own attention; almost magical, it was a lovely chill-out space for us. I doubt there exists a similar listing in this site to this apartment.
However, beautiful as it was, the apartment was not very convenient in some aspects: the division between shower+sauna and toilet+sink+mirror is unusual and not comfortable. The kitchen is not well equipped and cupboards' organisation was strange. The mattresses were uncomfortable, and lightings in the apartment seemed to be lacking in evening time.
To sum up, in my opinion, the apartment's advantages overweigh its shortcomings. In its current price it is a great option for accommodation in Berlin.