I'm not sure, but your trans is a built circle D trans so it's apples to oranges with mine. I am a member of 6l80etuning.com, I pay the $99 annually to access his knowledge.
He specifically mentions if you have a Circle D trans, DO NOT touch the shift pressures. Since it sounds like you were not happy with your tune, I wonder if the shift pressures got messed with.
"From the above you can see I change most pressure values to match a 2010 CTSV. I then add 20 psi to Max Pressure, and set Max Pressure B/Max Clutch to 300 psi. I set Max Line Pressure in gears 1-4 to 279 psi. I max out the last two cells for all Base Shift Pressure Upshift pattern modes.
Do Not do this on the latest generation of Circle D transmissions, leave them stock. The latest internal mods only require you run stock pressure. You will need to check with Circle D to see if you can run these values. For downshifts, I add 40 psi to the Power cells only. For CTSV, Corvette, and Camaro Tunes, you can set all Base/Oncoming/Offgoing pressures and Volumes to mirror a 2010 Base CTSV tune see (
TUNING FILES). Again, check with Circle D before you do this. You can try it on the G8, Escalde, and Trucks, but they seem to be real finicky."