We had a wonderful stay at Sergio's apartment. Sergio is really nice and available, and the apartment had everything we needed for a comfortable stay (including cooking). Also, it's really well located, in a very calm neighbourhood, but with all the transportation we could ever need right by our doorstep (the most famous attractions in Oslo's are just a 10 minute bus or tram ride away). Addittionally it has a supermarket right by the corner and one of Oslo's main attractions os just across the street - the Vigeland Park. If you're looking for a place to stay in Oslo, we definitely recommend staying at Sergio's apartment. We surely will when we visit Oslo again!