We really couldn't have asked for a better and more responsive host than Ola, he helped us sort out a problem without interrupting our stay. I really can't say enough good things. The apartment itself was immaculately clean and well equipped if like us you want to cook your own food. The train connection from Oslo airport is very straightforward. I can't comment on transport into the city centre as we walked everywhere. But there seem to be lots of buses and trams in the area. We couldn't be happier with our stay and wouldn't hesitate to stay again.