Christos‘ appartment was very nicely decorated and he sent a useful description so we could find it easily from the airport. Count about 1.5h travel from the airport if you take the metro (it runs only every 30mins).
The area is residential and we took the subway almost every day to see the sights in athens. It is also walkable but count a brisk walk of 30mins to reach Sytagma square.
Christos‘ family was very helpful throughout and we would stay again! Thank you Christos!