Everything JC and Fred wrote over there apartment is true. It was even better than we had imagined. They are very friendly in communication and responded quick on the reservation request.
We had a wonderful time in Oslo. There are good public transport possibilities from the apartment to the center of Oslo. We visited the National Gallery, Museum of Contemporary Art (nice photo collections), Astrup Fearnley Museum and the Museum of Science & Technology.
We will return to Oslo to see more and hopefully we can stay again at JC and Fred.