The apartment is very unique! You will feel right at home with all the small decorations and small convenient tools (ie. iron, books about Greece). The in-unit washer was particularly helpful for us, because we were in the middle of our 1-month trip.
I’ve also stayed in Athens 3 times and this was by far the best location I’ve stayed at. It was much quieter and less touristic than the centre, but the centre can be easily accessed by walk or metro.