I came across this response, about tuners, from the SRT engineers in a 2008 chat session. How do you guys with tuners respond to it? SRT Engineer's comment: "I would not spend the money as most of the aftermarket tuning packages we have evaluated may put spark in or take fuel out of the wrong places and create durability issues."
As an ex-tuner who worked with GM engineers, I can say that the SRT engineer is correct. I've seen plenty of poor tunes. Plenty of people running tunes that damaged their engines as well.