The apartment is great!! It is even more pretty when you see it in person than in this photo! The room, bathroom and kitchen where always very clean and well equiped when I was there.
As the announcement says, location is the highlight of this place. It is very close to Oslo Central Station (5 minutes walking) where you may find public transportation to everywhere in town. Also, in the condo street there is a bus and a tram stop, that help a lot!
Martin is great! We arrived at midnight and still he was up and ready to take us to our room and give hints about the city, where to go, eat and drink!
Some downturns: The room lacks on air circulation, the only air entrance is the window, so you either have it opened or it gets too hot. At the same time, since it is super central, the street is pretty noisy, so you want to close the window to avoid the outside noise, but it gets too hot. Since I had ear plugs, that was no problem to me.
Also, the apartment is in the 5th floor and there is no elevator there.

I defnitely recommend this room!