We booked the Ostraco though Small Luxury Hotels, and were due an upgrade if available. When we arrived we were greeted warmly, but the first room we were given was very clean, but very dark and did not look over the sea - this was presumably a side sea view ! The room also could not connect to the advertised free wi-fi. We requested a change of room and although they had said no upgrade was available, they moved us to a suite on an upper level, but further away from the reception. Although this room was very nice and looked onto the sea, we were still disappointed as the complex did not meet our expectations from their website description. Fuerthermore we still could not access wi-fi. We stayed 5 days, hoping they would change our room, and although they claimed to be overbooked we knew this not to be true from the darkened rooms.
The pool area and breakfasts are the best aspects of this complex. Wi-fi is terrible and the location is a bit too far from the town of Mykonos - we only the walked back up the hill once !
After we informed them that we were checking out early and moving to another hotel, the staff became very unfriendly ! I don't think I would recommend this hotel to my friends.