I cannot recommend Casa Sofia highly enough. It exceeded even our highest expectations for Santorini and was the highlight of our Greek vacation. The location is unparalleled, in the single most picturesque corner of Oia - you will be the envy of every tourist coming by to take pictures of the view while you sit out on the patio drinking wine and eating cheese. The inside of the house is clean and comfortable, and Vasilii, the care taker, could not have been more helpful or accommodating (carrying bags up/down the stairs, recommending restaurants, arranging transport to and from the ferry, etc). We only wish we could have stayed there longer!