If you are going to Oslo and Alberto is available, book him!
Everything was superb: he was very welcoming, he was able to adapt to our early arrival, the room is huge, very comfortable and clean. We were allowed access to everything we needed: kitchen, bathroom (great shower by the way), living room area with a large TV set.
The location is the best we've had so far. Everything is at walking distance and the neighborhood is full of options if you want to cook or grab a bite nearby. Buses and tram around the corner if you need to go farther away.
We'd definitely book Alberto again! Highly recommended!