My XJ600 SECA II has a D&D exhaust, made in USA Texas. Its a bit loud, but the bike loves it. Shop rejetted the carbs, mileage on the bike is never under 50, and I got 59 on a trip, in light rain, with 'very' spirited riding. It's a shockingly good bike. I am thinking of turning it into a reverse trike, as it doesnt' get ridden enough, but would make a great donor bike. Also, my front forks are in need of a rebuild, so its either fix them or change things up.