We enjoyed our stay at Irene and Apostolos' place. It's well located, walking distance to the Acropolis, syntagma square, etc.
The apartment is big, nice bedrooms, clean, with almost everything you need to be comfortable as a family (full kitchen, towels, fresh sheets, travel cot, high chair, cable TV, Bluetooth speakers, etc).
Irene was quick to respond to all my queries and went above and beyond to make our stay with kids pleasant and comfortable.
As other reviews have said, it is on a main street with a "sex shop" visible across the road from the living room. So if you're looking for a charming tree lined street, this isn't it. But the convenience more than made up for this for us.
Thanks to Irene and Apostolos for sharing their home with us.