We stayed as a couple with our one year old child at Theo's and it was a very comfortable stay with 2 spacious bedrooms and a baby cot as well. Theo welcomed us on arrival, arranged airport pick up and gave us good tips around Athens. The one short flight of stairs down to the apartment was managable. Facilities were as described.
The location of the apartment was amazing and everything was within walking distance including the Acropolis and the Olympic stadium. There were lots of food options next door and within 10 minutes walk. Highly recommend this apartment if staying as a family.