he's just comparing the setup of the inner silencer in both (5Zigen&Jic) exhaust systems that results in quiet operation.

 

I have the 505 bullet in sus not ti , cost was a factor! Loud is a personal prefference and I do not feel it to be as loud as some claim . USDM is definitely quieter than JDM versions because they include a resonator in the mid pipe section. This is the units only defect as it is so wide there is maybe 2mm of play in the channel and that = clanging on take offs and down shifts...solution ...wrap resonator in header wrap so it fits nice and tight.
The exhausts are very nicely made . I give it durability snaps for having stainless straps to hold the hangers on instead of weld which can break off and tear your piping. both the resonator and the strapping are not pictured on their website in case you're wondering , unless they updated the pictures.I have yet to put the silencer (supplied) in it in two years but am sure it would make the wife happy so I won't.
Your choice comes down to looks and noise factor. My sus weighs 16 pounds , the TI 11 if I remember and they offer sus piping with a ti can too on the bullet , don't know how much less$$ that is so factor that in if weight is an issue to you.
JV

 

does it require a jdm downpipe?

 

Mine bolted right up using the stock gasket , however, one of the aluminum manifold type bolts snapped on me so a quick trip to the dealership found me paying $2.50 for the bolt (couldn't find a perfect match at the Pep Boys) and ...get this...almost $3.00 for the nut. Now the nut wasn't in stock so they cross refferenced it to a manifold nut off of a M5 bimmer. Theese are locking nuts , BTW, which is why I didn't just grab one out of my spare nuts (lol).
You should have no problems....I attract problems.

Note I ordered a USDM version.I am sure a JDM version may require The JDM pipe. Zeal motorsports/JIC Magic USA will answer that for you.