Definitely a value for your Euro especially in Santorini. The sunrise view from the patio was excellent and the secluded location of the hot tub below was very nice. The house was clean and the bed was very comfortable. The showers were excellent and had all the amenities any short term travelers would need.
Two things to note: the property does not have a full kitchen, only a toaster, mini-cooler and coffee maker. As we were there in the low season this prevented us from preparing hot meals for ourselves. Also, while the hot tub in more secluded than most in Oia, there are neighbors immediately next door separated by a partially closing opaque glass door. While we were not troubled by our neighbors while visiting, just know that you will not have 100% privacy in the hottub.
The inside of the house is very quiet and totally private. There is almost no natural light as it is a cave house but it is well lit and very cozy.
For the price and location it is a bargain go Oia or really anywhere on Santorini these days. Hopefully they add a hot plate in the future but we would both happily return.