For you guys that keep asking for videos of how this mod sounds, there's a before and after video at
YouTube - Vulcan 900 Custom Debaffled
You can compare that with V&H on the 900 at
YouTube - Vulcan 900 custom w/ vance & hines slashcut staggereds and the Cobra at
YouTube - Vulcan 900 Custom Cobra Slashdowns (de-baffled)
I think the Cobra sounds amazing, but you have to take into consideration that different cameras were used and they probably don't have the same audio recording capabilities. You won't be unhappy, no matter which you choose.