Apartment of about 40 sq meters is equipped with all usual modern conveniences and I did not feel like I'm missing anything. Air conditioning was very decent indeed - must for summer in Athens. It is full of light, spacious and equipped with nice, modern minimalistic furniture. Good internet connection.
It couldn't possibly be situated in a better place. Some 300 m from Syntagma Square, and maybe 350 from Monastiraki. Getting from the airport was as easy as it gets. Then it only took less than 15 minutes for us to enjoy narrow streets of Plaka, restaurants, shops and bars. A very charming church of Kapnikarea is situated about 150 m away.
A nice balcony, full of plants, was a big plus. You could see one third of Acropolis from it. Our host gave us an excellent crash course on Athens and its places to go and see - a very nice gesture.
I would definitely pick this place again (and I probably will :-).