Stayed at the Rica G20 for 3 nights in Oct 2011. The location is ideal, 10 minutes walk from the bus/train station, just a few metres from Karl Johans gate, and within easy walking distance of the Opera House, City Hall, Aker Brygge and Akershus Fortress.
The room we were given was small but not as small as I had expected based on some of the reviews read on here. The room has a mini bar which we used as fridge for our own drinks, a large and comfy bed and a TV which showed only Norweigan channels and BBC world news. The room also had an I-pod docking station but ours didn't seem to work! Note that there was no iron or kettle in the room which was a slight downside. We stayed in Oct 2011 when the outside temperature was quite cold but found the room very hot at night, and the temperature control in the room didn't seem to have any effect. Another slight issue was the trams outside were quite loud and could wake a light sleeper. The shower was very good and soaps, shower gels and shampoos were provided.
The breakfast was excellent, a great selection of cooked meats, eggs, cold meats and cheeses as well as fresh fruits, yoghurt and smoothies. Tea and coffee were served to the table.
Overall at around £110 a night we found this hotel to be very good value in a city as expensive as Oslo. You may find the room a little small if visiting for a longer stay but we found it perfectly adequate. If you want a good location to allow you to see as much of Oslo as possible on a short trip then this is the ideal hotel.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC