The room was clean and as advertised. We never met Anders, and only introduced ourselves briefly to Joanna (it's more like a hotel), so that was a bit different from our other Airbnb experiences in Europe. Still, they were responsive to our messages, just not really present on the property (that we could tell). It didn't matter to us, but some people might prefer a little more personal interaction with their hosts.
Unfortunately, the internet was pretty spotty in our room. We didn't get the advertised wifi network at all, but a different network Joanna sent us did work intermittently. The TV room had better reception since the router was in there, but even something simple like browsing Facebook was pretty difficult from our room. That was probably the only disappointing thing about our stay.
On the plus side, the laundry machines are very convenient, and the apartment's location is great (right by the royal palace/Karl Johan's gate). For the price, you really can't beat it. I would recommend it to friends staying in Oslo.