Quite simply if this place is available when you are planning your trip to Santorini, don't hesitate, just book it. If its not available I would suggest changing your dates to when it is. I don't think there is a better location in Oia where you are minutes from all the action but totally private and the views are as good as anywhere if not better. The sunset views that thousands come to see every night and pack the vantage points around the town, are amazing from here and with all the comfort and convenience of being at home.
The house itself is 2/3 levels but works really well. The terrace/pool area is great and although small the pool is perfect to cool down and still enjoy the incredible views. The beds are really comfortable and bathrooms are big and well appointed. Kitchen is small but perfect for what you need and to be honest there are unlimited restaurants within a 5 minute walk so the kitchen is a bit redundant.
This part of Santorini is dominated by steps and most accommodation requires walking up and down some steep access. However this place is perfectly located at the highest level so access into town is pretty easy in comparison.
Judy was great to deal with prior to arrival and she was kind enough to leave us with a few treats when we got there. She organized transfers and gave us a good general briefing about the town when she met us.
This is a very special house in a very special place.