This apartment is a perfect choice for you if you're looking for something clean, convenient, and very modern.
My girlfriend and I spent a good amount of time months in advanced looking for the perfect place to spend our 2 week vacation in Oslo. We decided on Julia's apartment after messaging about details (she is very quick with responses despite being a flight attendant on the other side of the world).
She had her friend pick us up from the central station (only a 20 minute train from Oslo airport via the Flytoget). The central station (and the rest of central Oslo) is only 15 minutes walk from the apartment, and the closes metro station is only 5.
The apartment is even better in person than the photos. It feels much more spacious than other one bedroom apartments that I've stayed at. The kitchen is ready to cook anything, the shower is hot and good pressure, the tv in the living room is large and gorgeous, and the bed is very comfortable.
If you want a stress free stay in Oslo go wit Julia's apartment. You won't be sorry :)