As others have said, the hotel is well placed within Oslo and is best reached by the public transport. Taxi from the airport can be eye-wateringly expensive (meter maxed out at 900 NOK which I've been led to believe is due to Oslo Cabs having a max fare for such a journey despite us still being 10mins out from the hotel, private cabs would charge for the whole distance and could be up at 1500 NOK!).
Check-in staff were pleasant and efficient getting the registration process over and done with in a couple of minutes, and were explaining the breakfast/restaurants while sorting out the room keys. I'd been booked a room at a corporate rate for a company I was visiting (approx 1500 NOK/night) so had not idea what i was actually getting - turned out to be one of the 'Executive' rooms on the 26th floor, which when you compare the description with that on the website is actually a Standard room. Mind you, with breakfast included (free to the room if i wanted it via room service) and free access to the movie channel its probably slightly better deal than what you get for booking the standard room direct. All of which is fine if you plan to be antisocial and never leave the room, but wasn't something I was likely to use. However, in comparison to the 2000 NOK/night they list on the RadissonBlu website guess I shouldn't complain too much.
Room was quite small, but nicely laid out with the bed being central to the room, a couple of easy chairs and a desk that backed on to the headboard of the bed. Bed was very soft and took some getting used to and the duvet seemed about 12in too narrow for the bed. I'm sure this is all part of the contemporary style of the room and isn't an issue if there is only one person sleeping in the bed, but if two adults were in there then one of them is not going to be under the covers for much of the night. A second duvet was in the wardrobe, so you could get around this oddity.
Bathroom was nice and light and clean and the shower had plenty of pressure once you'd worked out which combination of lever pulls routed the water from the taps to the handheld shower head and then from that to the fixed shower head up on the wall.
Unlike some, I found the hotel wifi (free throughout the hotel) to be reasonable fast and it never once dropped a VPN connection (if only more hotels would do things this way rather than charging an arm and a leg for flakey connections).
Breakfast buffet is reasonable with a good range of both hot and cold options available, staff are friendly but very busy as it it can get very crowded. Finding a table can be a problem if you're not there early on - something others have also noticed. The restaurant on the 34th floor also has a limited menu, but it feels expensive for what you get. Whilst the food is nice, I was less impressed with the speed of service - 30mins from sit down to taking the order, and then an additional 60mins until to food arrived. This would be understandable if we'd ordered a lot, but for just 2 main course dishes you'd have thought they could be quicker. The restaurant had a reasonable number of diners, but wasn't full, so I doubt an overwhelmed kitchen was the reason.
So, overall its a nice clean friendly hotel, and a corporate rate on the room made it cheaper than it would have otherwise have been, but i still question whether whether its worth the money - perhaps Norway is just expensive per se.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC