We got a very good deal online ($25/night) and for that price this hotel was outstanding. It is a resort, with all rooms having a view of the water and their own private porch. We were in the hotel (as opposed to the bungalows) and the room was clean and well appointed. There is wifi throughout the building, and a nice spa with sauna and cool pool. Weather was too chilly for swimming but the outdoor pool and ocean beach are both very nice, though the beach furniture was a bit in dis-repair (possibly because it was the end of the tourist season).
Tips: You can walk to town in about 25 minutes and it's not a bad walk though there is no sidewalk for much of the way. Otherwise you pay $5-7Euro to get to town. In town there are cute restaurants and some grocery stores. If you want to see the island or plan to go to town often and don't want to walk, consider renting a car or scooter.
We took the ferry over from Turkey, and from Vathy town where the ferry lands, you can catch a public bus to Pythagorio. If you tell the fare collector that you are going to Proteas they will let you off before town, just in front of the entrance to the resort. Busses do not run very often so be sure to check the schedule. We tried to catch the bus back to Vathy from a stop up the street from the resort, but in spite of their general reliability it did not show up and we ended up taking a cab to be sure we were not late for our ferry back.
Nice common areas, nice tennis court.