Gadget and Ron (his page is linked from Gadgets) have done some wonderful R&D work on the supercharged 3.4 V6. They've taken the hard knocks to test a variety of performance mods and report what works and what doesn't. I've replicated much of their current set-ups and it's working very well in my truck (
http://128.83.80.200/taco). I trust the information on their page more anything TRD or any of the aftermarker performance tuners put out.