John was an excellent host - very friendly and attentive both before and during our trip. A few days prior to our trip, he sent us a lot of things to do/book before hand. We regret not planning better because we did eventually want to do a sunset cruise. We decided this last minute and we're not able to get a reservation on the 2nd and last night we were there because it was all booked! I recommend you do this with John beforehand so you don't miss out.
About the place: it is a shared balcony but you have separate areas. We also has the section that did not have an external hot tub but we had a third and separate section for us where we can lay out on beach chairs. You have to walk through your neighbors section in order to get to this other area, may have been awkward but honestly, we spent very little time at the room and did not care to lay out in the balcony (our trip in santorini was only 2 nights). We also had a hot tub in the room and we're not charged like the other reviewers. John also did not charge us for the transfers.
The room is also on the Caldera side so it is a taxing walk to go up and down the stairs but It is a small price to pay for the view! You will also have a similar walk if you stayed at other caldera cave houses so this walk is not bad at all. Just as a side note, I thought we would have a sunset view from out balcony - but we don't. It is hard to have both a caldera and sunset view, which John explained to me. However, this is not a huge problem at all. The cave is very conveniently located from spots where you will have a perfect view - steps from sunset point.
The accommodations were also clean and had a kitchen,etc.
Side tip: pay attention to the meeting point for when you need a transfer back to the airport. He had us meet him at the post office but we got lost and could not find it when we had to be picked up. Sorry John!
Overall - great stay !! We loved the place and santorini is amazing