Below, I will explain why I can give only a medium rating, which is only partially due to the apartment and mainly due to arrangements outside the apartment.
I would like to start with the positive issues:
The apartment is very very clean. The towels and linen smell nice and everything needed is taken care of. The roof top is exceptional and great and indeed, Akropolis is visible from afar. I travelled with my two kids and we liked the neighborhood because of the calm street and nice walking distance to the major sights. It is obvious that the crisis hit the neighborhood and some stores are closed but I like calm neighborhoods for sleep. The apartment is spacious and could accommodate four visitors by size but
the sofa is not very comfortable and the apartment is more for two than for three individuals. Within the apartment there are two moldy places, one in the bathroom and one in the major sleeping room, which is very unhealthy and has to be removed. The sleeping room has no AC but a ventilator, while there is an AC in the kitchen. It’s ok, the AC cools the apartment.
The following behavior is not acceptable to me: Konstantinos offered us a Taxi service from the airport to the apartment, run by his friend. He said it would cost 40€. Our plane arrived 40 Min later. The friend was waiting for us and we entered the taxi. After we entered the bridge to the highway the talkative driver told us that the trip would cost 54€, something not known by Konstantinos and which were predetermined by law. I had to accept, since we were on the highway and I was travelling with my two kids. Otherwise I would have thanked and changed the car. When we arrived at the apartment, the taximeter indeed showed only 40€ but the driver told us that the night fee and the toll had to be paid by me (today I know everything was a trick and we were lied to, which I will explain shortly). I wrote Konstantinos and explained why changing the conditions after a service has started and breaking the own word is not acceptable for me. Konstantinos justified the behavior by the planes delay and said this would be like that everywhere in the world. I told him, that he knew our arrival time since I wrote him 2 hour in advance and a service offered from the airport should accommodate some delay. But the main point is, that the justification by the taxi driver was not the delay, it was the toll we had to pay. Konstantinos offered us to pay the 14€ back but I told him that it were not due to the money but the behavior of tricking people I dislike. So, I didn’t want any further contact. For our trip back to the airport I found a service recommended by trip adviser and guess what: I could prepay by credit card, a very professional driver with a large Mercedes took us and I was only charged what was written on the website (Airport Athens Taxi) and I paid 35€ to the airport. The difference between 35 and 54 Euros cannot be explained by the night shift and neither by the delay since both phenomena are accommodated by the professional Taxi Service, Airport Athens Taxi.
If you decide to stay in Konstantinos place, do not use his friends Taxi Service ( VIP Athens Taxi). Konstantinos himself was very flexible with check out and if he removes the mold in the apartment, it is a place one could stay, what I personally would never do again.
PS: There is no washing machine within the apartment but somewhere in the building.