I chose this location as a long-term stay during the COVID19 pandemic when we were mandated to spend more time than usual at home.
In my opinion, it was a wonderful apartment, very well suited for extended periods inside. The place was spacious, quiet, benefited from a lot of natural morning and afternoon sun (both on the terrace and in the sun-facing rooms), and was in one of the best central, but not touristy, parts of Athens.
Working was facilitated by a very comfortable large table in the lounge as well as a working 'shelf' in the second bedroom. Wifi was available everywhere, although due to the size of the apartment, it was naturally strongest near the router in the lounge.
Nearby the apartment there are plenty of transport options, plus a good selection of supermarkets and specialist food shops, and for when everything is open again, ample bars, restaurants and other amenities. The neighborhood of Koukaki is a superb, livable neighborhood where you can get a good sense of really living in Athens rather than just merely visiting. One of the nicest aspects of the neighborhood was its proximity to the acropolis and the hills surrounding the ruins, which served as an easily accessible break from work in the middle or at the end of the day.
The agency managing the property answered queries very promptly and were very accommodating when I needed a flexible checkout. They also responded to and acted upon a request for an additional kitchen tool rapidly, making the experience seamless.
Highly recommended, both during and, I am sure, after pandemics ;)