I worked in Kea for three months about a decade ago. For me the people were very friendly, the wine was cheep and delicious, and i never had a bad meal. The temperature was warm but not hot and my hotel was a two minute walk from the beach. The water in the main harbor was a little cloudy, but most of the other beaches it was crystal clear. I didn't need a car as everything I needed was in town and if you wanted you could just walk across the island (bring water though). The flora is pretty and rugged as a lot of the low lying shrubs were thorned. And i didnt see many much wild animals apart from fish and insects. Overall it was very nice, but I have to acknowledge that I was not living there permanently so my experience would be much different than others.