I'll open up this review by saying that our stay at Ro House couldn't have been better. This was the first time we (my family and I, three people in total) tried Airbnb and we were a bit insecure on how things would turn up being in reality, but to our surprise it beat our expectations.
The house is big and quite airy, with comfortable furniture and beds. The bedrooms were beautiful and the view from both (!) terraces of the sunset was one of the highlights of our stay. Why go and elbow your way through the crowds in Oia to see the sunset when you can sit peacefully with some food and drinks and have a direct view of the sun going down. The house seems to be newly renovated and was extremely clean and there was no humidity or smell to speak of. The bathrooms are clean and also big, and the kitchen comes well equiped for cooking. Anything ingredient wise you have to buy yourself, but Katia and her assistant left us plenty of water in the fridge, as we were landing extremly late.
We met all the greek neighbours and they were all lovely people, and as for the location, the house is very close to the main pedestrian walk overlooking the caldera. There are two supermarkets nearby and plenty of places to eat nearby. The parking lot is also at a 3 min walk, though it gets very crowded so if you rent a car (please do if you stay more than a week in Santorini, public transport is very patchy), make sure to catch a spot when the parking lot gets empty around 9pm.
On a side note, expect flight delays and a very disorganized airport, so even though Katias assistant was very kind to wait up on us, be sure to tell them both it'll take time to make your way from the airport to Oia, especially if you rent a car and drive there (a lot of the roads are not lit at night, and are very narrow and winding).
Katia was very detailed oriented and she gave us a ton of local tips, from restaurants to events and tours. She was also very quick in answering messages and any questions we had. On top of it all, she has a lovely personality, and very friendly and proffessional. The last thing I should add is that late check-in and check out were possible for us and everyone was very accomodating. The price tag is definitely expensive, but you do get a lot for it, especially if you split the cost among five people, the max occupancy. Give this house a try, you won't regret it!