Kostas was one of the best hosts I've ever had - he was very responsive, answered all our questions patiently, provided some recommendations for us, and even helped organize a free ride for me to my next accommodation. We were thirsty when we arrived and he jetted off to buy us water!
The cave house is wonderful - it was clean, and had a really nice fresh/modern but traditional feel. Really beautiful accommodations for an excellent price. The two bedrooms are separated and so each couple has good privacy and separate bathrooms.
If you have health problems note that it's a 5 minute walk to the main Street and 10-15 minute walk to the caldera facing side. I personally enjoyed the exercise!