Whilst I don't get to play with the big round engines, I do get a lot of pleasure from the Wasp Junior (P & W R985). If the sound of a single 985 flying over a few feet above me on a still day in open water is anything to go by the tone of the multi row engines must be incredible.
Whilst radials may not be as reliable as turbines, listening and feeling the regular beat is very reassuring offshore.