I have a MR762SD package with the 2 piece O.S.S. It 'seemed' really cool at the time, and IS nice to have the OSS can marked MR762.....but it IS kinda loud. Ironically, I learned through @mew a buddy's research that their GEN 4 is really their Generation ONE (clever marketing) and now the GEN 5 is really their Generation TWO. The 2 piece SRM sound reduction module and BPR Back Pressure Regulator was a really neat idea, but i'm not real impressed. Kinda loud, not "great" consistency in grouping, though I did limited testing. I have no idea what the HELIX is capable of.
I already had a SUREFIRE RC2 SOCOM so I ran it until the OSS was out of jail and THAT can....although expensive, is a DREAM!
Just my $.03