Clean and enough space for one person. Everything was working fine.
Christos takes care all problems for the whole staying. For example, I had a problem with the Wifi during my staying and Christos just came to have a look in the evening. He has tried everything to solve the problems and at the end, I could use the wifi from other wifi router. So, I would always recommend Christos' room, if some of my friends will be in Athens and find a room.