The new 5.0 are AWESOME, I still haven't put an exhaust on mine but I put a cold air intake and a SCT tuner on mine and it sounds completely different its alot louder!! I think im going to put the Magna Flow Street Series on mine, I don't want it obnoxiously loud but an aggressive sound!!
The new 5.0 is an amazing motor. To get that much power from the factory from only 5 liters of engine without boost is unreal. Best sounding? No, cammed/stroked big blocks win that one. Borla is expensive because it is higher quality than anything else out there. I will put nothing but Borla on my vehicles.