It is a 5 stars studio, very clean, cosy, quite, best location in Oia and the view....mind blowing! The apartment is so much more than we expected. There are some steps to go there, but not a problem.
Above all Theo is a 6 stars host, he was a traveling agency by himself helping with absolutely everything (transfers, tours, restaurants...). He sat with us when we arrived and showed us all the nice restaurants he recommends and places to visit in Santorini. As other said before in their comments: Theo is the first person we will call if we come back to Santorini. Thanks again for for everything!
And Theo you are right Santorini wines are very good!