We spent 3 nights in Marianne's apartment. The apartment is not far from the city center. (8min from the Oslo Sentral with the tram)
The room is very cosy, clean with a lot of space for your staff. There are the tea or coffee for you on the table, city map or any useful brochures. Bathroom also nice and clean. You can use the kitchen and the fridge.
Marianne is very nice person, you can have a nice chat with her and she is also respecting your privacy.