Xristos is a very friendly host. One time the electroc kettle broke, we just informed him and he immediately brought a new one into the apartment.
Air conditioning is essential in the greek summer heat (sometimes over 45 celsius) and this room has it.
Showering sometimes a bottleneck if all the rooms are booked in the apartment especially because you need to turn on the water heating a few mintues before.
Archeological sites are in a 20-30 minutes to reach by metro so if you are okay with using (8.20 euro for 5day ticket) public transport then it is good.
Athen's beach area is around one hour of travel by public transport (the 5day ticket is also valid for this).
Overall I would recommend to stay at Xristos's place.