Spiros replied to all our messages within a few hours at the latest. Although we did not meet him in person, his relative handing over the keys upon our arrival was kind. The apartment was comfortable and clean, and its location is excellent: there is a small alley full of restaurants nearby, and the Acropolis itself is not too far away even on foot (about 20 minutes walk at a comfortable pace). I definitely recommend this cosy flat. :)