Akis was extremely kind and available. We did not meet personally, but he arranged for us to easily pick up the keys at a nearby bar. The flat is big, clean, and new, with a fully equipped kitchen (there is a microwave, and Akis offered us to chose whether we wanted it replaced with a stove), a comfortable bathroom, and five double bedrooms (three of them with windows). The WiFi works properly in all rooms.
Some very minor elements could still be improved (e.g. a hook for the shower head), but they are certainly due to the flat being still new. Since the washing machine--which was new--was not working yet, Akis kindly offered to provide an alternative through the housekeeping.
Overall a very good experience and highly recommended.