The flat is well-equipped and has an elevator and a huge balcony. It's in a great neighborhood in a nightlife area, so there's lots to do just outside the flat. Keep in mind that this means noisier Friday & Saturday nights, but nothing too loud unless you require absolute silence to sleep. There is a large balcony you can dine on. There is free public parking on the streets outside the flat within a few min walk, but since it's a nightlife district, you may end up having to park 10 min walk away if it's later in the evenings.
Konstantinos was a great host that was very friendly and responsive and helpful for any questions or needs that we had. He even gave us updates to disruptions to public transportation that were helpful to know. I would be happy to return to Athens and stay here again.