My fiancé and I had the pleasure of staying at the Afroessa Hotel. Everything at the hotel was top notch. The staff, the service, food, drinks and overall cleanliness of the hotel were very impressive. If you are looking for a place on Santorini not as loud or busy as Fira or Oia then I highly recommend staying in Imerovigli at the Afroessa Hotel.
We went all over the island and the view the Afroessa provides is second to none. The sunset is breathtaking. You can see the stars when the sun goes down as well.
The staff made reservations for us at multiple places. Set up shuttle service to and from the airport/port. Helped us with our bags. Answered any questions we had. They smiled and wished us well each time we saw them and I could tell the genuinely meant it. This is hospitality at its finest.
If our travels ever take us to Santorini in the future, we will book the Afroessa Hotel again. I can't say enough good things about this hotel. The only regret I have is we could not stay there forever.