I booked Ioanna's Cave house during the week of my 40th b'day. My boyfriend and I had a wonderful stay. The location is absolutely stunning and the Cave house itself is really lovely. You have amazing sunset views from the rooftop and apart from the crowds at sunset we found it really quiet and private. Ioanna and her husband were really lovely. They gave us really precise directions and were at the apartment to greet us. They provided a lovely bottle of local red wine too which was a nice touch. The Cave house was really comfortable and clean.
I can highly recommend Ioanna's Oia Cave house!