about sport mufflers?

well its clear most sport mufflers appear to have dual outlets but were there many manufacturers?....are they desired for looks, sound or performance?...I have the chance to get one at a good price...dual in/out...some surface rust....should I be concerened about the manufact?...are some known to be too loud for street?...are they a worthy upgrade to a stock 2.2 T or only on upgraded engines?Is it silly to install on orig. 114k heat exchangers/manifolds( in good shape)?....should I just get SSI heat exchangers?....sorry for all my ?, just don't want to pass up a good purchase and I want to add some more throttle response to my T..thnx

I paid $250 for a new RSR style exhaust from Mittel Motor in Germany. The sound is awesome on an RS motor

Stay away from AJ USA sport muffler - very poor quality.