I had a great time in Sebastian's apartment! I stayed for 2 weeks and found everything I needed in the apartment. The space is cozy and decorated nicely. On top of that the location is in a great area with a tram line right around the corner, alternatively the walk to the city center is also not too long.
Sebastian is also a great host who is easy to reach and always ready to help with anything. Definitely recommend staying here if you plan to visit Oslo!