Well after reading that the majority of our power gain comes from the "grapevine" mods and dollar for dollar the exhaust systems don't add up to much other than a better sound I'm starting to lean towards the HMF slip on. Construction wise it looks like a Muzzy and will probably sound relatively similar, which is mainly what I'm going for, I just want to be noticed in traffic and if the carb mods are where the big power gain is then it doesn't matter much which pipe I use. HMF has already posted their dyno runs on their forum and after Adrenaline posts his with the Muzzy I will probably make my decision but if its only marginal I can't really see the extra $180 for the Muzzy or Big Gun.