Themis was really friendly, the beds were comfortable and the breakfast on the first day was so big it fed us for lunch too! We were also supplied with robes, wine glasses and a fresh bottle of water every day.
The hot tub is set to a temperature that I think is heated by solar panels so as it was the start of May it was unfortunately too cold to use 2/3 nights we were there. As others have said the view isn't great from the balcony but the iconic Imerovigli cliffs are only 5 minuites away.
The location was good, with plenty of restaurants, a takeaway, pharmacy and a shop nearby. It's within walking distance from Fira and you can also hike to Oia. There is a bus stop outside the house but the buses on Santorini are pretty unreliable.