My experience with Xrysa and Tolis has been excellent: they have been very helpful during all of my stay.
The apartment is located exactly halfway between Ano Poli and the newest part of the city (the seaside is at a 15min walk distance). It's perfect for students as it's only 10 minutes away from the AUTH campus. The view of the old city at night from the room balcony is what I loved most.
It's perfect for one or two people, and it's comfortable for both short and long stays.
As I said, Tolis and Xrysa have always been available both before and during my stay for any problem or question.