Just reprogrammed my 09 G8 GT and it makes a little more power off the line. I am most impressed with the added gas mileage. Was averaging 17.7 now 20.8!

I too am looking into a programmer for mine, but am torn between the Superchips Cortex and Diablosport. What made you choose the Diablosport? The only mods I have are Vararam and Magnaflow cat back exhaust.