Konstantinos's place was perfect for our week-long stay in Athens. The location is within walking distance to a metro stop and a very hip neighborhood with lots of restaurants, bars, and cafés. Just be warned: there are lots of hilly streets and stairs to get up to the apartment (but that's all over Greece, so might as well get used to it!).
Konstantinos was an A+ host. Very responsive to all messages, he even went above and beyond and gave us recommendations for places on Syros, how to get to the apartment from the Port, and where to find taxis.
We would absolutely stay at his place again!