Stelios/Nasos's place is wonderful! It is in the best location - right near Monistiraki square, accessible to all of central Athens. The balcony has a wonderful view of the Acropolis.
The apartment is well equipped & clean, the check in was easy, Nasos was in touch to check in and make sure all was well.
Note that it is on a busy street, and close to a church, which has bells in the morning. If you are noise sensitive, this won't be the best place for you. If you don't mind late night noise and want to be in the heart of everything, stay here!