I've got the original set on my car. They are a pulse timing technology set with twisted fire cones in the collectors and AR cones built into the primarys. This is a different technology than a scavenging collector type system.
Without the 6 foot resonator I installed, it sounded like a freakin' NASCAR. O-M-G it was loud (sweet v-8 note, but friggin' loud). With the resonator and Flowmasters, it's just about right.
I was having a problem with the CE light due to AIS and downstream O2S, but with the new SCT Tuning, I have fixed it. It now has 30lb injectors and 150hp of nitrous. The tranny is still a work in progress, but at least when my converter gets done and the gears go in, I'll have the right tuning for it.