We had a great time in Håkon apartment. I would not hesitate to stay here if I visit Oslo again. The apartment was nice, and quite large. The area is quiet, but only a short distance to Grünerløkka and public transport.
We had an easy time finding street parking right next to the entrance (though expensive as everywhere in Oslo).
The apartment is on the third floor without an elevator. It was no problem for us, but might be for some people.
Håkon was easy to communicate with, and answered quickly.