Steve, the SSC stops the whistling which you’d otherwise experience with the upgrade. FPM375 definitely improves the mid range, produces more pops and bangs generally and they are also more pronounced! In combination with the Remus it’s excellent.
The FPM375, SSC and any aftermarket zorst sounds amazing – for the money I went Scorpion…thanks to Kenny I got a valved cat back with black ceramic Daytona tips for an amazing £750 on Black Friday last year – for the price its impossible to complain.