I booked Irina's apartment for my aunt and her family.
We were very satisfied and the apartment was better than I expected. I would recommend especially for 3 people (best for 1 couple + 1 single) who wish to visit Oslo in more than 2 days. The location is the greatest peculiarity, in fact the apartment is a few meters from bus and tram stops that run through the whole city. With a weekly bus ticket (just 300 kr) you can travel all over Oslo. Furthermore Irina has been easy to contact and welcomed us in a friendly manner.