Great location, just a short walk to the metro or around 15 minutes on foot to the Acropolis Museum. Plenty of interesting restaurants in the neighbourhood too: Annie, SVOURA and Mani Mani.
Chilling on Konstantinos' balcony - with the great view of the Acropolis - is fantastic, so make sure you have snacks and drinks :-)
We did not meet Konstantinos at checkin, but there were no problems finding the key: It took a while before we found out, that the wifi and password are on the backside of the router - and be aware that there might be a timer on the boiler: It made for a rather cold shower experience, but as we were there on hot days, it was not too bad....