Independent testing nicely done by Jannetty Racing on the V6 with various cai's is here. Data is getiing old so all the current players are not represented and some manufacturers have refused (uhm, I mean requested not) to be evaluated.
https://spreadsheets.google.com/pub?...=1&output=html
HP tuners is still dangling their carrot that a tuning package is coming for the LLT, but it has yet to materialize. I can't help but continue to hold my breath as they would likely have a superior product and I would wait til you're done with your bolt-ons in the hope they come thru.
Vmax iceolator doesn't give a great deal of peak power increase but more than makes up for that with improved mid-range performance- like 20-25 more hp/torque in the 3-4K RPM range (where most people operate their car). It's a relatively easy install, inexpensive, and the best bang-for-yur-buck IMHO.