The apartment is perfectly located in a residential area, far away from the noise and walking distance from the most interesting places in Athens. There's also an underground station 3 minutes walking from the apartment, and you can reach the Acropolis in 1 stop, Syntagma Square in 2 stops, and the National Archaeological Museum in 3 stops (8 mins). I only took it once because I was in a rush, because you can perfectly go on foot and it's a pleasant walk.
The apartment is fully equipped with all of the necessary stuff, not only to spend a few days but also live in it.
Kostas gave us all a lot of recommendations for places to eat and beaches, and he double checked that our stay was perfect and offered his help whatever we needed. He also left coffee pods and croissants for our breakfast on the next day, such a perfect host!
I can only say that you won't go wrong booking this place :)