Most of the aspects of Ephelia are great, the location, the food, (most of) the staff, the ocean etc. So why only three stars? Mainly two reasons:
1) mosquitoes. Everywhere. In the room, in the restaurants, at the pool, at the beach. Swarms of mosquitoes that attack you relentlessly. I realize that there essentially is a swamp in the middle of the resort, so of course there will be mosquitoes, but given the location the resort really needs to do more about this. They fumigate the island every few days, but that's clearly not enough. More fumigation, bug zappers and mosquito nets in the rooms and so on are needed. Or at the very least warn guests to bring strong repellant.
2) the dive center. We only did one dive because the other days the dive did either not happen because of too few people or was booked out. On top of that the dive master was very unfriendly und unhelpful, she didn't even want to tell us which dive site we were going to. Having been diving at other Constance properties we expected much more and were very disappointed.
There were some other minor annoyances (e.g. breakfast supposedly starts at 7am, but if you actually go there at 7 half the food is not ready yet and the staff are still preparing everything), but the mosquitoes alone make me not want to stay here again.