Katerina is a wonderful host, who lives on the property (this should have been mentioned by AirBnB, though). The apartment is part of her complete house, and her many cats lounge around in the shared courtyard. She is warm, friendly, and even left fresh fruits and croissants and jam for us!
Since the houses are not marked in Vothonas, she helped arrange our transfer from the Thira port to her apartment at an additional cost (Eur 35). Our driver, Kate, was waiting for us at the port and is a very helpful and cooperative woman.
Katerina's apartment is thoughtfully decorated with items from her personal/family collection. Needless to mention, the house was sparkling clean.
Location is in a quiet place in the centre of Santorini. The village Messaria is about a 15-minute walk from the apartment, from where you get buses to Thira centre or Kamari beach (Eur 1.40 per person per side). In Messaria you also have a couple of departmental stores, restaurants, and cafes.
However, the GPS cannot be trusted to reach the apartment. Each time we followed it, we landed up elsewhere. So, please carefully note down the pointers the host mentions, or make mental mark-ups while walking through the area.
In summary, we had a wonderful stay in Santorini, thanks to Katerina.