We stayed at Konstantinos' place for three nights whilst in Athens. The location is excellent with lots of cafes and restaurants on the doorstep and very easy access to all of the city's main attractions. The apartment itself is up on the fifth floor though so it's quiet despite being in the busy centre. The view of the acropolis are fantastic from all floors and the inside is spacious and clean. It's also equipped with outdoor furniture so you can have breakfast in the sun!
Konstantinos was really easy to communicate with and was very accommodating with our schedule. Great place for anyone looking for a lively, airy and central place to stay!