Your quote of GT Premi is one that simply isn't accurate. ...
Wrong or not, just like Creedog, I can tell a difference in the sound. It's not a "self fulfilling prophecy". I could hear a difference before I even had my R, so it's not like I'm playing favorites for the R over the standard GT350. I love them both! There is an audible difference. It's not impossible that Creedog and I (and millions of other people) have really sensitive hearing.
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I find it hard to believe that I am the only one wanting to do this. ...
You're not the only one who wants to do it. It's just that a lot of the people get discouraged/distracted by "That's crazy! If you just do ABC, you can save XYZ dollars and have the 'exact' same thing." Which I'm really surprised Tob wouldn't be onboard with your thinking, considering how much time and money he spent retrofitting a brand new '13 GT500 carbon fiber driveshaft to his '09 GT500 when he "could've just bought an aftermarket carbon fiber shaft" and been done with it since there's "no difference" in the driveability and reliability of an aftermarket shaft.