I bought my RC51 used, and it had D&Ds on it. Between the noise of those pipes and my Shoei RF-1100, my ears ring after riding, even with the best earplugs. It really puts lead in your pencil to wind it out past 10k, though. I really do try to keep things tame in residential, and no doubt, the fuzz can hear me coming if I'm getting enthusiastic.
The D&Ds came in real handy getting even with my asshole neighbor. The fukin d-bag called the purple meanies to shut down my dad's 60th party at 7pm on a saturday, due to noise. I was pissed man, almost spent the night in Rita. So I decided that I needed to properly warm up the RC for 5 min at full choke(yes, it's a FI bike that has a choke) every morning at 4:30 AM before leaving for work. I made a new parking spot right next to his bedroom window, and made sure the pipes pointed in his general direction. A couple months later, HE WAS GONE!