I have an 09 SG, a friend also has one. He has SE slip-ons, and when we put our bikes side by side, my stock exhaust was as loud, but not quite as deep. Seriously, the Screaming Eagle slip-ons made very little difference.
I then replaced my stock mufflers with a set of Rush baloney-cut slip-ons, and the volume and tone are perfect (for me, that is). Deep, really do bark when opened up, but not so loud you can't hear the stereo and get pulled over all the time. Another friend put Reinhart slip-ons on his Road King, and they're deep but they don't "open up" when you twist the throttle.
It's all in what you like, try to hear other's bikes, ask what pipes they're running. You can go to Youtube and search, but IMHO, it's not a good way to tell how they really sound.
Good luck,
Bone