I stayed for 10-11 days and everything was great.
I recommend to everyone. You can just book it and not worry about nothing, suitable for short or long stays for sure and a value for money.
The area is safe, nice and quiet, around you will find bakeries, take away places, cafes and supermarkets. Green areas, including the beautiful Lykavitos hill is walking distance. Syntagma and Monastiraki is also walking distance, I walked several times and really enjoyed, approx. 30 mins walk away. Metro station is ten minutes walk.
The apartment is nicer and bigger than the pictures show, everything really clean, i have to say it was the cleanest Airbnd I ever stayed at.
Maria is an excellent host, responds very quickly.
I would definitely come back.