We really enjoyed our stay, the apartment is in a perfect location, everything is near and at a max 20 min walking distance (Lycabettus hill, Acropolis, Syntagma square). Also a great neighborhood, with lots of restaurants and coffee bars.
Thanasis is very pleasant and welcoming. The apartment is very clean which was very important for us since we were with kids.
I recommend it, and will book it again when coming back to Athens.