Great space to stay in Athens. Would recommend getting a taxi to the apartment if carrying many things, otherwise metro is fine.
While the apartment itself is amazing, the walls on all sides are thin and you can hear a lot of noise from other residents. At night this was not a problem but as soon as the morning comes be prepared to woken up from 6-7am. The bedroom is next to the communal stairs so loud steps or conversations might prevent you from resting.
Balcony is amazing and worth coming back for. Wi-Fi speed was extremely slow and difficult for working remotely.