I know this has been discussed to death but I just want to clarify what I think I have learned on this forum.
I am looking to swap out my exhaust (factory pipes with Rush slip on's) to a full system. I am not looking for a cosmetic upgrade necessarily, but a performance one. As far as performance goes it seems to me that a LONG pipe length, 2 into 1 system is the way to go. Something like this:

http://www.patriotpipes.com/images/M101112S_LG.jpg

From what I understand shorter pipes and 2 into 2 pipes (even if they are crossovers) don't work as well!?!??

Anyone have any experience with the Patriot Defender pipes?

 

No experience with those pipes, but I put a Thunderheader on my bike and am really happy with the results. What I feel (seat of the pants) is better throttle response and slightly noticeable low end torque. From what I've read, a 2-1 manages the back pressure more and helps with torque. If I'm wrong, someone chime in and say so.

 

I have the bassani road rage and i love it. It seems to make great power.

 

I love my D&D 2-1 and I think for performance and looks they are hard to beat.

 

If I understand your statement about cosmetics and you're really considering performance first. Just buy a system from a reputable (V&H/Bassani/D&D/Rush/Cobra/Patriot/TH/ etc...) vendor that has "some" back pressure. Straight pipes (no baffle) sound wicked loud, but you will lose some performance. 2-1 is arguably a slightly better performer than 2-2. If you consider "sound" as part of the performance too, now you're talking differences between pipes. Good luck...