I had a really nice stay at this flat and the host was very fast to respond when I had questions. The location is beautiful and not too far from the center and spots like the Acropolis and Panathenaic Stadium. Checking in is very easy and the flat is nicely sized. It is also well-equipped with towels, kitchen utensils and bed sheets, so you feel right at home. Keep in mind, it is a half-basement, so the flat isn't the brightest, but you have enough lamps to make up for it. It also can get quite cold which might be nice during a stay in summer, but I was here in March and the room cooled down a lot, so bring some warmer clothes for inside, as the heater is controlled by the owner of the building (which is typical for Greece in general!).
Overall, I recommend this flat as a person that travelled alone!