Teo and his wife are both very friendly and welcoming and communication with them was easy. The apartment is lovely, looks exactly as it does on the pictures, but it is obviously not a flat anybody lives in. The hosts do provide some basic equipment though, which is perfectly sufficient, and also things like coffee, tea, sugar and a bottle of greek red wine which I thought was very kind of them. The flat is clean, everything works well and the bed was comfortable.
The neighbourhood is beautiful too with many restaurants and cafes, which I enjoyed. The downside to this is, that in the evening it's a bit loud. But the windows are well isolated so if you can sleep with your windows closed this is no issue.
The flat is only a few minutes away from the metro station Omonia and walking distance from the inner city, which is very convenient. Also, if you go to Athens to do the marathon as I did, a pick up point of the shuttle bus to marathon is close by so you can walk there.