Powroll also has a nice stainless system that runs a supertrapp muffler.
The BBR pipe is loud because it's designed for closed course racing. It also isn't spark arrested, so nobody should be buying it for trail use anyway, right??
What we've found after testing a gazillion exhaust systems at Poker Runs over the last few years is that the disk system mufflers tend to be quieter on the four strokes than the two-stroke style silencers.
The quietest new systems we've tested (on lots of different bikes and quads) are the Supertrapp IDS 2 and the White Brothers (thier new one, I can't remember the name right now, sorry!).
BTW, after dyno testing and track testing, we found the TTR 125 does better with the stock headpipe and just a muffler modification (either Powroll's thrust chamber, or homemade) if the engine is stock.
Once you install a bore kit and camshaft, then the pipe is needed.