I got my 2011 RKC back and now it's sporting V&H Dresser Duals with Hi-Output Slip-ons. The sound is incredible. The deep growl sounds great and when the rpm's jump these pipes BARK! They look pretty dang good too! Here's a video of the sound and a few pics!
http://www.youtube.com/watch?v=vlOYfgS933c
http://www.youtube.com/watch?v=vlOYfgS933c