An amazing place to stay and explore Oslo from. Very convenient for getting to the trains, buses, and metro, all of which are included in the (zone 1) travel pass with your stay.
Room and bed is very comfortable and the bathroom and shower are good. The bedroom has perfect blackout curtains which is such a help in the long days of the summer.
Terje is very nice and helpful and can let you know places to go and handy tips. Pus the cat is beautiful although do be aware you will end up with plenty of white hairs on things.
Overall, I can't imagine why you'd stay anywhere else in Oslo. I stayed 4 nights and could have stayed longer because Oslo has lots to do!