Megas Gialos is perfect if you want to get away from it all and live the simple life - the local (stony) beach is small and almost deserted, with wonderful opportunities for diving/snorkelling and climbing across dazzling rock formations, there is a lovely taverna nearby, and that's about it - we and our children LOVED it. Of course if you rent a car there are also many other great things to see on this fascinating island, including the fascinating city of hermopoulis.
The apartment was great with an absolutely stunning view. Nikos and his family were excellent hosts, extremely friendly and helpful. Just 2 minor points: as others have commented, there is a guard dog that barks a lot, so if you don't like dogs maybe it's a problem - as a suggestion maybe find a place for him during the day that is not directly in front of the door/pool? . Second we were restricted to using the pool only from 9-2pm, i guess because we shared it with the other guests. Again, no problem as we were at the beach anyway, but should be made clear beforehand. But all in all a wonderful experience, highly recommended!
Thanks Nikos!