This place is everything we imagined. The view and studio are truly picturesque, and Oia is beautiful...easily the most stunning place I have been.
The studio is close to the main pedestrian street, and 5 minutes from the castle where everyone watches the sunsets.
Theo is a great host. He will arrange car/transfer services when you arrive in Santorini, porterage if you need it, and he will suggest great restaurants and activities. He was especially helpful to us...he provided a phone when my US mobile couldn't make calls in Greece.
One tip I have is to let Theo arrange a transfer service from the port or airport when you arrive. It will cost 30€, but it is cheaper than a taxi. And the busses are confusing. So just let Theo help you.
This is a great place. You'll be happy you chose it.