The Yosh RS-4 Stainless/Aluminum is a two piece system, not a three piece; it scavenges the stock heat shield from the stock pipe, yet does include all the mounting hardware needed (spacers, bolts, and grommets). The fit was spot on and mount-up was a piece of cake.
I rode the bike at my vet novice pace, and also had pro rider and DR tester Ricky Yorks ride the stock and ‘piped’ bike back to back at pro speeds. We both had similar impressions, even though Ricky rides in the high rpm and I ride in the low rpm - the Yosh gives the stock power a boots across the board without changing the stock bike’s power personality. That is, you’re still looking at a machine that does its best work in the midrange, but now there’s more boost. Yorks said the pipe didn’t help the bike rev further up on top but appreciated the across-the-board boost of what he estimated at a five to ten percent.