Henrik and Fredrik's apartment was really amazing. They've done a great job furnishing it. It's not uncommon for things like appliances, door hardware, etc. to really have seen some wear at AirBnBs; in contrast to that, everything in Henrik's and Fredrik's place was spotless. (Incidentally, the shower was particularly nice.)
I researched neighborhoods before my trip and, while the location of this apartment didn't show up in my research, I couldn't have been happier with it. Oslo is so walkable that I was able to walk to everywhere I wanted to go very easily. Particularly, I walked to Grünerløkka and the city center every day I was in Oslo and both were only a few minutes away. I was even able to walk with my bags to and from the train to the airport!
Henrik and Fredrik were really nice and their apartment is a perfect home base from which to explore Oslo.