Nestled in a canyon in the center of the island, Katerina & Emmy have created a really fun place to stay in what used to be a wine making cave. It's beautiful, clean, and quiet place to stay. It's located fairly close to Kamari beach, and quick access to Fira. Perissa is also fairly close. Oia, the other main hub, is about 30 minutes drive. All in all, the island is tiny, so it's a fairly central location to all relevant areas.
As a host, Katerina & Emmy are great. Katerina lives next door, and though she doesn't speak great english, she was very hospital (Emmy manages the Airbnb communication for her).