I gave 5 starts because I couldn't give more. If you are looking for a cozy, comfortable and clean space to be in, that's the flat you should choose. The location is just perfect, you are 3 minutes walking from the metro station - which you will not use as you are walking distance to absolutely everything.
Great food and bars all around. Supermarket is also super close. The Acropolis is only 13 minutes walking from the apartment and you can already see it when you turn your left after living the apartment - which is nice.
Everything worked fine. We had a problem with the coffee machine and in less than 10 minutes it was replaced with a new one.
Also, as we were there to work for a week, we needed good internet connection. We had a issue on Monday and it was fixed at the very same day.
In other words, you don't need to worry if you have any everyday problems. They will answer you very quickly and solve the problem.
The communication with Eirini was outstanding, all the responses were super fast. The checkin and checkout went smoothly.
Absolutely recommend it and will definitely stay there again when coming back to Athens.