I also know only the Hilton. Have stayed several times there ... I agree with lemieux66 .. always had a nice room etc. The location next to Frauenkirche is great. I always had a car, there is an underground parking at Hilton. There are several restaurants at Hilton. We went to the Italian one, food was OK, but not great. Last time we visited VW Glaeserne Manufaktur, arranged by Hilton, very interesting.
berlin_style:
When you stay at Radisson, let us know how it was...