Great location close to trains, buses and trams. Mona provided great tips for walking and enjoying cultural, tourist, outdoor and foodie spots in Oslo. Villa Paradiso pizza is excellent. Very quiet area and bed comfortable for a good night's sleep. Just make sure to get on the regional network train to National theatre station to exit at Henrik Ibsen gate, the metro station is extra 15 minutes walk uphill.
However although the apartment is very nice, for me I found it and the private bedroom too crowded with furniture etc to be relaxed & comfortable. Just a matter of personal preference and not reflected in other guests comments.