The building is in a great, central location. It's a lovely old building that's been renovated. The apartment has a nice balcony overlooking the courtyard. It's close to a lot of places you might want to visit in Oslo as well as the central train station. There's also a wonderful bakery called Backstube at the corner that makes the most divine pastries.
Frederik was quick to respond and very attentive and overall a great host. I would recommend the place.