(+) The flat was great, very nicely decorated, with taste, Nice high ceiling and confortable. Very clean as well. Has AC. Perfect for a group of friends or couples. Price is very attractive in that sense. Location is quite good as you are close to almost everything you want to see in Athens.
(-) elevator didn't work, the building itself is quite old and quite dark, in the flat there is absolutely no view, and not much sunlight goes in. It's also one of these instances where the photos are too good compared to reality, they are a bit overselling. The worse thingfor me is that I had a terrible night of sleep because of the nearby bars, they were super loud until 3 am. And windows do a terrible job at preventing the noise.
Overall, this time, it was very convenient for us to rent this flat but I'm not sure I would rent it again.