Lucas' apartment was a great place to stay in Oslo. It's stylishly decorated and in a neighborhood full of interesting cafes, bars and parks. Connections to/from the airport and the centre of Oslo were quick and easy.
Lucas was very welcoming and offered me some good tips for places to go. He had his friends over for drinks on one of the nights I was there. They offered me a glass of wine and we chatted about life in Norway - I almost felt like a local.
I would highly recommend this as a place to stay.