We stayed for a week at Firas' place and enjoyed it a lot! Even though we arrived late, we had no problems obtaining the key and Firas left some notes at the apartment with hints and infos.
The place itself is located about 5 min by foot from Oslo's main train station and a lot of grocery stores. We encountered the place clean and found everything we expected from the add. There's plenty of space for 2 and the kitchen is well equipped with coffee machine, water boiler and a dish washing machine. We had some problems with the Wi-Fi on the day of the arrival but Firas got it fixed on the second day immediately.
We can recommend this AirBnB to anyone!