Fredrik's Airbnb is AMAZING. It's really stylish and has everything you'd ever need while staying there. The bathroom is amazing and it even has a washing machine! The bedroom (great bed) and the living room are really stylish, this has to be one of the best Airbnb I've ever stayed on. Check-in and check-out was really easy thanks to William the co-host who is an amazing host. He gave me tips about everything in the city and was really flexible with the check-out time.
The location is great, you are a few blocks away from the city center and at the edge of Grünerløkka which is one of the coolest neighborhoods in Oslo.
I recommend staying here a 100%!