My bud and I both have 07 RGs, both have exact same mods, dyno'd and race tuned by the same top tech at Harley. Sept he has rinefart true duals and I have LSR 2-1. We both topped out at 114 mph on the 6 mile flat straightaway, between vegas and pahrump, NV. I barely pulled away from him with the 2-1. My take, the 2-1 might have little better low end but no difference at the top, at least in our testosterone test. Get what looks and sounds good to you, the rest is a wash IMO. FYI, The dude at RB is convinced that backpressure is restrictive.