This was definitely a great experience. Mary meticulously takes care of the apartment and she is a very kind host. Metros is only 5 minutes walk and eventually you can walk to center, which is only 20-25 min far by walk. Furthermore the National Museum, which is absolutely worth to visit, is literally 2 min away form the apartment.
The apartment is clean and nicely decorated, there is a good vibe to stay in it. Furthermore all the equipment works perfectly. Mary's apartment is highly recommended if you need a place for short or long let in Athens.