I had a great experience staying with Gunnar. I was in Oslo for over two weeks and Gunnar's flat was a comfortable place to retreat to after work each day. The sofa bed is probably better than some actual beds so don't let that put you off staying here. The flat is located very close to a metro stop that is serviced by the number 3,4 and 6 trains. It takes about 10 minutes to get to the city centre. Gunnar himself was a great host - he met me on arrival and made me feel very welcome. You'll struggle to find better value accommodation in Oslo!