Dimitris was fabulous! The apartment is just slightly outside of the most touristy area of Athens (but within a 3-5 minute walk) so it's still quiet. The building is very secure, at night there are two locked doors for the building and a lock on your door. He was incredibly helpful for check in and super responsive! He let us store our luggage before check in which was awesome!
My only problems were minor, the beds are not very comfortable. It was fine for a twenty something with a good back, but if you have back problems, this may not be the best for you. And two, the hot water runs on solar power. Even though Dimitris told us how to turn on the back up hot water, after 2 showers, the third person was usually out of hot water.
Like I said, very minor things. Over all this place is in a great location and a great accommodation for what we paid! Would very much recommend!