Already have two Glock 19s... I'll keep them for now as I like the reliability and weight. Don't get me wrong... the Kimber is an excellent firearm and I do wish to add one to my collection eventually.
Need to get a H&K .40 for my wife... she hates the double stack mag on the Glocks.
Back on topic...
As to the exhaust, I happen to really like the stock SRT6 setup which is WAY more expensive (OEM) than the Base or Limited exhaust system.
If I get to the point where I have this as a track car only like HDDP, then I might consider it. But right now, for daily driving, I like the quiet when I don't have my foot in it, the soft rumble when I am accelerating softly and the "VROOOM!" when I get on it.