Lovely place - the location is superb, the design is stylish, the beds are comfy. The place is very clean, completely private, with no people walking right outside your window like in many other places in Oia. Waking up to those amazing caldera and Oia views every morning was the highlight of our trip. What I would say truly distinguishes this place is the communication and service we received - Danai helped us book an airport transfer, supplied valuable information on restaurants, where to pay least at the supermarket, ATM, etc, how to get to the Oia-Fira trail - virtually anything we needed she could answer accurately and rapidly. She made sure the place was cleaned once during our stay, helped us coordinate a car rental for a day with the best prices, and looked after us from beginning to end. It was an amazing feeling and made our stay in Oia very welcoming and smooth.
About the hot tub per previous comments - it is about 34-35 deg Celsius, meaning it's great for when it's warm outside but when we tried it at night when it was a bit cool and windy (October) it wasn't enough. I think it depends on what you are used to - maybe Europeans find it great but in Israel we are used to more in the area of 38-39 deg, so it's pretty subjective.
Bottom line - great stay in Oia, value for money, private concierge vibe - really would return one day and highly recommend.