Hmmm... Having heard a Scorpion and a Nismo side by side, that were both Popcharge, stock cats and y-back the scorpion isnt louder than the Nismo and the Nismo sounds far better and more meaty.. Also under load on the motroway, there is no comparrison.
Also! Sorry Chris, the rasps come from the heast shields above the cats (a quick seem weld or if your using decats or hiflows remove them) and the heat sheilds above the back box. I havnt removed the one above the back box yet as I need to find some non metal flexible heat shield. Its to do with the increased resonance of the thinner wall pipes. The one I have on now as its super light with decats has increased the rasp I had before... (Also think I get a bit of rasp off the grill on the rear of the CS bumper.. Think I need to get some sikoflex on that!