We spent one week in May in this apartment with our 2 children (3 and 5 years old).The apartment is exactly as described in the ad, nice with refurbished antique and local furniture, very authentic. And lots of place with the 2 rooms and the living room. Staff friendly and helpful.
Unfortunately the children are very afraid by dogs. The 4 dogs were not a great idea for us, even if friendly.
The place is normally quiet, but the first night, we have been waking up by people discussing outside at 5 am, maybe people from dormitory.
It would be great to add some deck chairs to enjoy the terraces, and some place and clothes pegs to hang out the washing, as there is lots of wind in Santorini.

The place is not far from Fira, maybe 20 minutes by walk from Fira, but the way is not pleasant. We have rent a car in Karterados.
The view of the caldeira is so magic, that it should be fantastic to have an apartment with this view. But not sure that it is possible at the same price that the apartment in Karterados.