If you can afford the extra $$ the catback is the way to go. From what I've seen from personal experience and what I've read in the forum, to eliminate the V6 raspines completely you got to replace the resonator. In this, Magnaflow and Corsa do a pretty good job, but Magnaflow seems to have the deeper sound of the two.
I love driving with the windows down and the sunroof opened just to enjoy the sound
I finally have the sound to back up the looks
The other day I passed an SS and the driver looked king of puzzled, probably couldn't figure out why my V6 sounded better than his V8.