Oia is incredibly beautiful but also incredibly touristy. Full cruise ships are let off and crowd the path down to the apartment. If you are expecting a true Greek experience, look elsewhere. The apartment is suitable, while missing some of the homey touches of other Airbnb's: water bottles, snacks, maps, or any kind of personal touch.
The location is good for the view. In the evening the caldera is beautiful (you cant see the sunset from here but the colors and view of the bay are unbeatable).
Airbnb is at its best when you feel like you are staying in someone's home; we never met John and it felt more like a hotel. His communication and coordination of transportation was excellent however.