The Epcos have a nice snappy sound much like an old 650 with the magaphone pipes that were popular in the 50's. They are loud enough, but not so loud as to gain you a collection of tickets.
I put mine on the bike at about 150 miles, so I can't really comment on the amount of power gain over the factory stealth pipes because I followed the runin rules very carefully. I can say though, the Triumph is noticably quicker than a new HD Lowrider with Vance & Heins pipes and a high flow fuel injection intake.
Another nice thing is that the Epcos bolt to the original Triumph pipe hangers, so you get no rusty bits.
