I stayed at the Radisson in Dec 2002, I had an overnight layover while changing carriers (Aer Lingus to US Air) before heading back to the states. It is a very nice hotel and was located off of the walkway between Terminal 2 and the train/bus station (you go through the station on the upper level to get to Terminals 1 & 3).

It was very quiet for an airport hotel, I couldn't hear any of the airport noise in my room, or anywhere else in the hotel.