I've got the Arrow 2:1 and at times like a little less noise then the pipe w/o the baffle. I found the baffle to be too quit so I simply drilled a hole in the end of the baffle. Enlarge the hole until the sound suits you, this ain't rocket science.
I also have a slight studder/surging in the 3k-4k range w/o the baffle, more them likely a reversion issue caused by running an open pipe. Baffle totally eliminates that studder/surge and does not seem to efffect top end power.
My Scram is an '09, 904cc, 12.8 pistons, 813 cams, tune/boy timing, PCV w/auto tune for fuelling.
The Arrow 2:1 and the Triumph tune were by far the best bang for the $$$'s. I should have been happy and stopped the mods there...
Regards, Paul