Matt,
Opinions are like "you-know-what", everyone has one. I've been into sixes since the 50s and still think a set of dual exhausts, running from a split exhaust manifold or headers, sound the best with good glass-pack mufflers, set up close as possible to the front and long 2" pipes out the back. That's the classic method of gettting that sweet six cylinder sound. To me, those Flowmaster mufflers sound like a forklift in a tunnel!