Nikoleta's place was lovely and was a great value (relative for Santorini). The location was far enough off the main walkway to be quiet, but close enough to be very walkable to all the restaurants and shops in the main area. The caldera view is nice from inside the home, but absolutely breathtaking from the hot tub.
We traveled with carry-on bags only, so the washing machine in the apartment was a lifesaver for us (it was actually a key factor in our decision to stay here). Be aware that this home has a very sensitive plumbing system (typical for cave houses). We didn't have any issues, but it's something to be mindful of.
Lastly, Nikoleta and Santiago at the front desk were incredibly helpful and responsive. They helped organize airport transfers (for ~30% less than the Welcome Pickups service), answered questions about the bus system, and more. We very much appreciated their hospitality.
Overall, this was a great place to stay in Santorini and I would highly recommend it.