I'm old (32) and I like my stock exhaust. It's funny how you can see the different stages in your life by looking back at the different exhaust systems.
I remember when I first got my '89 GT 11 years ago and I saved up for a Flowmaster cat-back. I remember how excited I was when I was installing them, and then how disappointed I was at how quiet they were. Then a year later I installed an o/r H pipe and my car sounded so good I almost cried.
Then in 2003 I just couldn't take it anymore. So on went a Magnaflow X with cats and cat-back. Still sounded mean, but not embarrassingly loud.
I sold that car in 2006, and when I started looking for another stang last year, all I could think about was throwing some Flowmasters on there. But now that I have my '01 GT I have to say I'm happy with it just as it is.
You know you are old when you think your stock exhaust sounds bad-ass!