The boss side exhaust is a bit "illusive" in its sound. I would say it is more for the driver to hear and enjoy vs. other people on the road. The exits are pointing slightly downward so the sound is mostly heard close by (cabin). Don't get me wrong, they sound like pure sex but if you want everyone in the neighborhood to hear you a mile away, they won't accomplish that. You will want to go the cat delete/LTH route for that.
That being said, I have inadvertently scared some people when driving side by side next to them and mashing the gas....quite a few now that I think about it haha!
What mufflers you are running, baffle, no baffle, etc in the boss pipes, will make a difference in overall sound. Your not just working one set of mufflers, you are now running quad exhaust, and with one pair open, and the other set, say stock mufflers, you will get an overall different sound than open boss pipes and outlaws on as well. My exhaust actually got quieter for me, inside the car, but it is just as loud, if not a tad louder outside the car. So not always going to be the same for everyone, cababah said his added more for the driver to hear, and for me, it took away sound.