The apartment is really very nice. Despite its small size, it has a lot of space which makes the overnightings pleasant. It must be mentioned that all the spaces were admirably clean (thank you!) which made us feel very comfortable staying there with our 3 months old child. Julie is a good host, very friendly and helpful. The area is fantastic, a few minutes walk to the beautiful Vigeland Park, and also a few minutes walk from the nearest subway station.
On the negative side, it has to be mentioned that the sound insulation is very bad, and on several moments during afternoon and early evening times there was noise coming from upstairs (running, jumping, objects falling). Although it is understandable that it is quite expected when children live above, I believe it should be explicitly mentioned in the description, as sleeping sessions of an infant could become a bit challenging.
All in all it was a very good experience.