We, a group of five people, stayed in this apartment for a week. Since we arrived in the middle of the night, we weren't sure if we would be able to check in - but the hosts were very accommodating and one of them came to show us the apartment and give us the key even thought it was the middle of the night.
The apartment itself was exactly as described - big enough for the five of us, clean and it had everything we needed, including a washing machine. From there, the next metro station is only a few minutes away and you can reach all the main attractions by foot in under an hour if you want to.
We can definitely recommend Vasiliki's apartment and wouldn't hesitate to stay here again if we ever came back to Athens! :)