Was wondering if anyone has experience with the Superchips Cortex tuner for GM products? Model 2950 is advertised as a one size fits all cars and trucks, gas or diesel. No has had a tuner for the 6.0L LS2 for the 2006+ CTS-V that I have found. Plenty for the 5.7L though. Any thoughts or comments about the Cortex? Anyone using it? Many thanks.