Constantinos always answered asap and was ready to help. He let us check-in early and thus made our first day in Athens easier. The little flat is located right next to the metro with direct trains to the airport, which was really important for us, because of the early return flight hour. We had everything that we needed through our stay there, all the small things, that make you feel home. As a bonus it has wonderful Acropolis view :) There's much nice places to eat in the area and it is not far walking from the main sites.
Thanks!!