Mark was very responsive! We had a bit of trouble with the heat at night (it was late November), but he was willing to respond to us very late in the evening to help point out we were pushing the wrong buttons. Very helpful in pointing out things to see and do (and where to eat) and was willing to go the extra step to get us to and from the apartment and be comfortable. Can't beat the patio and view of the Acropolis -- great place to just relax after a day of touring.