Great location, a 10 minute walk from the Acropolis. Very central location, easy walking to all the most central parts of Athens.
The apartment's a bit small but cozy. The heater is not super effective I think but Athens doesn't get all that cold. There's a space heater in the apartment to warm it up a little in winter.
The wi-fi works, not sure if it's fast or not because I didn't do anything that requires a fast connection.