Location, location, location. The apartment is located on a quiet and very nice street in Koukai - THE neighborhood to be in Athens as a tourist. A few minutes walk from the Acropolis but just outside the beaten Plaka area, so you get the tourist attraction in walking distance but get a local vibe.
The apartment itself is just as depicted on his page. Clean, large and well equipped.
Konstantinos is a great host. We had a little accident during our stay and Kosta and his father were super nice and helped us finding the right clinic to see.