We were very privileged to have experienced true Greek hospitality through our interactions with Orestis, who was waiting for us at the apartment as we arrived straight from the airport (even a little earlier than our checkin time). He gave us a good overview of the neighborhood and many useful tips on where to go (and not to) which got us very comfortable in our first visit to Athens.
His place is a renovated office suite on the top floor of the building in the heart of Athens that has been converted into a very delightful 1-bedroom/1-bath apartment with a view to the Acropolis from the North side. Although the entrance to the Acropolis and other sights is about a 20 min walk, we enjoyed walking everywhere through the markets (Plaka, Aagora...). it all felt very safe and bustling with people esp. during the Christmas - New Years' weekend.
Despite the size of the place (which is a bit small compared to the American standard) four us were very comfortable in his place. Our son took the couch while our daughter got the pull-out couch (all very comfortable). Kitchen was very nicely stocked but we only made use of the coffee maker (coffee incl.) and the microwave. Bathroom was a bit small (compared to American size) but served our purposes. we didn't use the washing machine that was there.
Best part of staying at Orestis' place was that he let us leave behind our luggage in the apartment when we traveled to Santorini for couple of days before returning back to Athens for our trip home. This saved us a ton of hassle. On the last couple days we rented a car in Athens (Sixt) to travel to Nafplio and to drop ourselves at the airport. Orestis had warned us about the difficulty of parking but we managed to get parking despite the New Year eve party rush at the restaurants below.