This apartment has two great things going for it: a terrific rooftop patio with awesome views, and excellent communication, service, and helpfulness from the people who run it. The rooftop just outside your door cannot be beat at this price (especially since there is a large awning for permanent shade) and the team of people who rent the apartment try very hard to make a guest happy (e.g., there were wifi issues that they were diligent about fixing; and they quickly responded to my requests and suggestions for things like coffee making gear, a clothing iron, and a cutting board). Also, everything is new and works well, including the air conditioning. Five stars on these points!
A couple of negatives, however, bring it down to four stars. The apartment itself is TINY. It has a little twin-sized bed, a tiny table with one chair, a mini efficiency kitchen, and an itsy bitsy bathroom. I was there in summer and exclusively used the outdoor shower, which is terrific if you don't need a ton of privacy for your showering. But that would not work in the winter. Two people would be extremely cramped here, and the bed is not really big enough for two to sleep in. The building is not great overall. The elevator broke down two or three times during my 2 1/2 week stay (it was usually operating again by the next day), which is rough when you're on the seventh floor. And the hallway lights were completely out on the second and third floors, so when I walked I had to use my phone's flashlight in order to see my way. The neighborhood is fine but does not feel extremely safe, and the building is on a moderately busy street. When I was there nobody else came up onto the roof (so far as I could tell), but it is accessible to anyone in the building.
Overall, I strongly recommend this apartment to a man traveling alone. It is probably too small for most couples for more than just a couple of nights. And I think most women would not feel terribly safe alone in the apartment. But it is a great place to host a small group of friends, for a cookout (there's a small charcoal grill) or some chill evening drinks to watch the sunset. So if you're coming to Athens and already know some people here, this could be a great place to bring them.
In short, I highly recommend for the right people, but know what you're getting into :-)