exhaust system

Hi everyone, i just want to know, what is the "big" difference between the Acura 2008 Tl type-s 3.5 L exhaust system (wich is double dual pipe) and the Acura 2008 Tl type-s 3.0 L exhaust system (wich is double single pipe). Is it just the sound of the car, what it does more of the other one...