Yannis is a very attentive host, always responds very quickly and was very helpful in organizing airport transfers and making sure that someone was there to meet us in the apartment.
The apartment, however, was somewhat disappointing. The beds and pillows are not very comfortable and I would definitely not recommended sleeping in them for more than a couple of days. The towels were old and showering was also a bit uncomfortable as the shower head could not be attached to the wall. The air conditioning in the only bedroom that had one, was not working.
Other than that, the apartment is located in a very nice square, with lots of restaurants and supermarkets. However, it takes at least a 20min walk to reach the nearest metro or sights. Luckily, taxis in Athens are very cheap!