I had a Turbosmart Supersonic Type 3. It was good, no complaints at all. Bit loud though so I returned to my stock plumbback and the car drives heaps better.
Just doesn't get wheelspin on the 3rd gear change anymore, just a little chirp now if I try hard enough.. So to those people that say they are not a performance part must be wrong. It obviously gave my car more boost after gear changes.
Still got the BOV if anybody wants it.