Our stay at John's place was wonderful. The location is perfect, on a quiet street at the foot of the Acropolis. John was in touch prior to our arrival, and we arranged a transfer from the airport as the metro workers were on staff. Note that his apt is only 3-4 mins walk from his place so very easy access. You won't need transit however as the place is walking distance to all the major staff.
John's place itself is very spacious, well equipped and decorated. He has thought of all the details and is a great host. Do yourself a favour and stay at John's apartment!