The apartment is conveniently located in a walking distance from the main tourist attractions, and it was easy to park a car next to it, and in Athens it is not often the case. The apartment is relatively small, but fully equipped including kitchen, a full-size fridge, high-speed WiFi, air conditioning, etc. There is a beautiful orthodox church just few meters from the door, and unfortunately the bells started to ring quite early on Saturday...
Although we didn't meet Konstantinios in person, he was very helpful and communicative and was immediately ready to assist at every time.
Overall we had great time in Athens!