We had a nice stay at Airat's place. The apartment is very nicely located, we could walk or take the bike (Citybike) most of the time.
The only issue for us was the check-in. Airat told us one day before our arrival that we can only do it on two different time slots of half an hour length. After telling him that these slots are not suitable for us he offered a third one which luckily was ok.
Also the kitchen is not so well equipped, so if you want to cook something we would recommend to keep it simple. However, this was no problem for us, as we decided to go out for dinner.

In summary, it was a nice place to spend two days in Oslo!