I stayed at Aktaion Hotel with my wife for two days, and had a pleasant experience. The hotel is very well positioned for those that don't want to spring to stay on the rock, and the options for food surrounding the hotel are wonderful.
Overall, our stay here was great. The room had a fantastic view of the rock of Monemvasia from one balcony, and the other balcony overlooked the small harbor at Gefira. In general, this was a great option, and I would definitely stay here again.
The only two notes that I have that could be improved were: The water in the shower is not very hot. Warm enough for a quick shower, but on a cold night in Greece, a hot shower is enjoyable. The other is that the smoke smell from other rooms can be pretty strong. It was not overwhelming, but at times those that are sensitive to smoke could have issues with the smell from other rooms seeping in through the door. Neither of these issues were deal breakers for us, it just depends on your preferences...