Hilde Maren and Snorre's apartment is FANTASTIC. I can not recommend it highly enough.
The place is very spacious, with excellent indoor space and lots of outdoor terrace space. It is beautifully appointed, immaculately clean, and in a 5-star neighborhood in Oslo. The street and neighborhood are stunning: safe, clean, beautiful. Our family (ranging from age 4 to age 70) loved the neighborhood for walks, coffee, bakeries, etc. And you are literally minutes from a bunch of transit options (bus and tram), making it exceptionally easy to get around greater Oslo).
This leads to one important suggestion: think twice before renting a car if you stay here! While there is sometimes a parking spot in the building courtyard, it has a very narrow entrance, and parking in the area is not easy. With such excellent transport right around the corner, we found that having a car was more trouble than it was worth.
Finally, the hosts are amazing. They were communicative before our stay and helpful when we had questions during our stay. They were nearby if we needed anything. Can not recommend them and their place highly enough!