Myself and my wife stayed at the cave house for 4 nights and thoroughly enjoyed ourselves. The place was charming, clean and well equipped for basic cooking and relaxing.
Plenty of terrace sun for the whole day. It's perfectly situated in the midst of Oia. A stone's throw from the harbour and sunsets and in the other direction shops, buses and restaurants. It's still far away from the main square to be peaceful and lovely in the evenings too.
The host Giannis was helpful and prompt to respond to our questions both before and during our stay. He helped arrange our transfers and recommeded great places to eat out. Highly recommended!