All - Great to see there is some renewed interest in the Arrow Slip On Muffler. All I can say is I love this muffler on the CB1100. Looks more like the stock muffler than the Staintune but about 3/4 the size of the OE muffler. You definitely want to pull the baffle out as the sound is simple awesome. Arrow obviously put the baffle in for US homologation so the muffler could be certified for use on the street. I did run the muffler with a stock setup an stock air box with K&N. The bike ran fine. I then got the mod bug and installed a PCV for better upper end fuel mapping and also closed off the air inlet to the PAIR valve in the air box to prevent that annoying popping you get on deceleration. The bike runs beautifully. No complaints.
For those looking to purchase, check Ebay as I saw a few vendors there that had this muffler for under $500. i Purchased mine from Riichmond Superbike and paid about $540.