We enjoyed our stay at Nina's place, and it is definitely a great value. There are a ton of bars and restaurants close by, and there are a lot of cool places to explore within walking distance. We really enjoyed Mathallen Oslo, which is an indoor market pretty close by.
Nina wasn't around during our stay, so we were able to use the kitchen and common areas without worrying about imposing, but there's enough space that I think it would be fine with everyone home as well!