This was really beyond our wildest expectations. We split our trip up into a short stay up in the middle of Oia, and then a longer stay down on the water in Nicoletta's place in Armeni bay. While we're glad we stayed for a few days up in the constant throng of 'grammers in Oia, down on the bay it was quiet, perfect, beautiful. The house was cute and beautifully decorated, and had everything that you could need. We spent several days just sunning, floating in the sea, kayaking, relaxing. The stairs up to town are not so tough if you don't mind the exercise, and if you prefer it's easy to call Alex, your personal boat taxi, and ride to Ammoudi bay where you can get a car up to town.
It was a serene and ideal vacation in Santorini... and though you may share the sea with a few yachts and one or two adventurous sunbathers, there is no place on the island where you can have such direct and absolute access to the Mediterranean sea as at Nicoletta's place.
(DO make a reservation at the restaurant - the food is great and they're very, very friendly... provided you have a reservation.)