We had a great weekend at Efthimis's place - the flat is very near the bars and restaurants of Psyrri, and within walking distance of the major historical sites, and downtown Athens. The flat itself is clean and spacious - but the truly special thing is the incredibly clear view of the Parthenon that you can enjoy sitting out on the terrace. Efthimis himself was good and prompt to communicate with, and was really helpful to us trying to arrange a tricky check-in, while coming from two different places. Highly recommended!