Christian and Jang were simply awesome, checking us in in a timely manner, giving us tips on where to go and maps for our journey in Oslo. They were so considerate that we found a nice welcoming tea+chocolate in the room (clean, with amazing tv and bed).
The zone of their flat (Akker Brygge) is the fanciest in Oslo, with sea and amazing restaurants/bars nearby.
Definitely 5-star and worth if you are going to stay more than 2 days.
Francesco.