The apartment was really compact, it was unfortunate that it was the wrong type for us. For us, the view is an important part of comfort, and there was no view outside in Malin's apartment.
Transport connections from the residential area to the center of Oslo are good - bus and t-bane (subway). However, you should get tickets in advance or use the mobile application, because there is no ticket machine at the local t-bane station, and it's impossible pay with a bank card on the buses (paying with cash caused problems on the buses because the drivers didn't always have to give money back).
Oslo is an interesting place to visit, amazing architecturally courageous buildings!