The flat is very clean, beautiful, and located in a great area which makes it easy to hang around the city. Giannis was also very quick in responses. Overall, I would highly recommend it.
There were two minor problems: first, there was no oven in the kitchen (because there was a nice balcony, we wanted to have breakfasts at home but we couldn't make it); and second, the main door of the building is a bit tricky in terms of getting it to open.