Major difference between the two.
The tbSTi is practically a stock muff with nice stainless tips.
The JDM STi for BP/BL is all stainless.
Modded WRX STi sedan stock quads are probably a little louder. (I have a set)
The TCP's a a proper stainless performance exhaust, mine are only slightly more refined than the straight-through PROVA muffs I got from cruisn and which Owen now has.
TCP's are awesome.
