DJRandom/Astroham, I've made myself up a set of straight pipes for my VE SV6 they sound a little quieter than without the mufflers on at all. Much less vibration through the car as the pipes aren't shooting straight at the car. No extra money spent. Imho perfect sound.
Before you add the straight pipe, may i suggest trying out dump pipes after the last flange?
Illegal or not I've had dump pipes on for about 9 months across ACT, NSW and QLD. Never been pulled over or even looked at twice at an rbt. A tip though, always keep a spare set of mufflers in case you get a defect.