So, Aris is an easygoing host with huge experience for accepting guests. He provided all necessary details about route from airport, offered me a transfer.
Unfortunately Aris had not arrived due to some problems and we were met by his friend - Sofianna. Sofianna was so responsive - she outlined for us on the map some popular places among locals like cafes, restaurants, bakery and also her favorite sights. Sofianna thank you for your politeness and patience (route from airport to flat took ~ 2 hours due shower).
The one and single issue which we encountered is the lack of heating in bathroom. We had to dry our towels on the balcony ... May be it was our problem and we did not understand how to switch it on.
In general the flat is excellent for short vacation in Athens.