Maria was a great host. I haven't met her in person but she was really helpful from the distance :).
She prepared a list of things worth doing in Athens. We were told were to go for great Greek food, how to get around in Athens etc.
We met Maria's husband Costas who showed us the flat and explained everything.
The apartment is very beautiful, clean, spacious and warm. It looks the same as in pictures. It is situated in a non-touristic area but is very close to the city center and Acropolis. The neighborhood is calm and safe.

We felt very welcome in their flat. I can surely recommend staying at Maria's and Costa's place.