What I noticed was that loud pipes doesn't give the deep/warm "Duc sounds", but i guess that doesn't matter to you.
Not true with my RR. That's one of the main reasons I love it so much. Not "obnoxious" loud, more like the awesome Duc note that's become more
Given the price of Boomtubes, I think I'd talk to a talented local exhaust shop about a true one-off before shelling out that kind of coin.