I stayed here for two nights. It was a little tricky to find, as the door to the hotel wasn't very clear but luckily they saw me in the street looking confused.
Lovely room, really comfortable and clean. It is quite dark, but that makes it good for sleeping! I didn't have an issue with noise even on a Saturday night - and I'm a light sleeper even with ear plugs normally.
Beautiful roof top, which I made use of to chill out, especially the day before my flight.
Brilliant location and would definitely consider staying here again if I'm in Athens.