We booked the apartment two days before our arrival. The owner confirmed our reservation immediately.
The communication with the owner was smooth fast and really helpful. Picking up the keys was exactly how it supposed to be without any problem.
We stayed in Oslo during the Christmas, apartment is really good located in calm area near by the grocery, tram and bus station but it takes 10-15min by the walk to the city center, so no need necessarily buy the tickets.
Unfornately we were surprised by only one cup for tea/coffee and really soft bed which may be not ok for everybody and we found used t-shirt beside the bed.
We enjoyed our Christmas time in Oslo in this apartment.