Prochamber will be quieter at normal speeds and RPMs than an off road H!
As far as sounding amazing, a 3" exhaust with 3.5" dumped bullets will sound horrible on a stock 5.0. The cars that sound amazing have motors to back the sound up, and a motor with big valves, big cam duration, and high compression will sound a LOT better than any stock motor. You could put Dynomax Super Turboes on a built motor and will sound better than Flowmasters on a stocker... Loud doesnt always sound good.
I will say my friend had a SCed LX a while back, with shorties, off road H and a Mac catback (simple set up) and this car was insanely loud. Loudest chambered muffler car I have ever heard.