Overall, a great choice - easy walking distance to Fira (with lots of shops and places to eat) and within striking distance of Imerovigli also. Alex was extremely helpful (both with check-in and various tips for the area) and very communicative.
The room itself was very nice - it's very humid inside (since, you know, it's a cave), but there is a drying rack out front that you can hang things that need to dry. There is a great view of the eastern/non-caldera coast as well.