My brother and I stayed at Sotiris's apartment for six nights over the New Years holiday. Although the apartment is small, the place has everything one might need to live comfortably for a week or so. Everything was very clean, and all of the appliances operated without issue. For two travelers vacationing on a budget, this place has an excellent value. In addition, the location is wonderful. The Acropolis Museum, the Acropolis mount, and the Temple of Zeus are all within a 15-20 minute walk from the apartment. My brother and I also had no problem walking to the Plaka neighborhood and the public transit hubs from the apartment. On top of the value and the location, Sotiris is a wonderful host. He met us promptly when we arrived, and he greeted us with Christmas treats. Sotiris also provided us with a list of wonderful one day trips on public transit from Athens.
My only advice for this place is that it does not cater to travelers looking to cook in the apartment. Although there is a toaster oven and a panini press, the place does not have a stove or cooking pans and pots. However, Athens has wonderful restaurants and cuisine, so this is really a blessing in disguise.
10/10 would recommend!