This is an excellent apartment, fantastically located for visiting all the main historical sites in Athens.
Though do beware, as noted by the host, it is located in a busy commercial area.
The room overlooks Ermou St - which even during the week, will have loud buskers until very late in the night, overnight street cleaning / rubbish collection occurs, and people walk up and down the street around the clock.
We also unfortunately stayed during a time where there were noisy building works going on during some early mornings and afternoons.
So I would not recommend it for those who may want an early night in bed, or are light sleepers.
Otherwise, it's a great spot to stay surrounded with lots of amenities. The apartment is very well kept, and has all you need. Check-in was quick and easy and the host communicated the instructions well.