Great location and great flat.
Not ideal for those who mind the noise from the bars/restaurants but you should expect this if you decide to stay in the center of the Athenian nightlife. Also, there are no window shutters, just curtains, so keep that in mind if sleeping in pitch black is your thing.
In general though the flat looks amazing and is comfortable and clean and equipped with quality breakfast.
The host is very helpful as well.
I would stay there again.