We spent 3 weeks at Vasilis's place and we had a very great time. For sure the terrace is a must to enjoy a book or breakfast with the beautiful view. We loved the area, close to Lycabettus hill, with nice boulangerie, market and bars close to it. It was easy to reach the center (40min walk or many buses), as well as Pyreus or Airport with the metro nearby.
The flat was good for two people, nice space. The bed were not the most comfortable though, especially the single beds with thin mattresses and one with a noisy bed springs.
We didn't meet Vasilis but he was reactive with the messages.
This is a great place to stay for several weeks