We had a great time at The Copper Door when we were in Oslo to visit the biathlon World Cup in Holmenkollen. The studio is very cozy and nice located, next to and between two metro stations who will bring you to the city center and Holmenkollen very fast.
It is nice to stay here and you hardly have to bring anything, because almost everything you need is already there! The kitchen is also very complete so you can cook easily, with the base ingredients and stuff other guest left which you can use.
Jannike is very nice and kind and you can ask her for tips and help, which we didn't need because we could find everything very easy and it was all very clear. She has books and maps in the house with nice tips what to do and where to go. The Vigeland park is very close and nice to visit.
Again, we had a great time in this very nice place. Sometimes we didn't even want to go out because it was zo relaxed to be there ;)