Been a while since my last update here but I finally flashed my PCM with the PCM of NC tune and the throttle response/acceleration especially from low speeds is well worth it. Drives very smooth and has an extra kick in the top end. The Flashpaq ended up not being compatible with my 2010 flexfuel motor.
New GM Performance exhaust arrives on Thursday, I'll post pics/video of how it sounds. Looking forward to it, I think Hummer should have made the exhaust tone more like the Escalade than how muffled it is stock.
I didn't like the Dynaudio mids I installed so new mids are on the way, Audible Physics Arian 6.5's. Not looking forward to performing any of this install work with how cold it has been but oh well, it is a labor of love.
The gm performance exhaust makes the truck sound more like a v8. But personally its not loud enuf. Ive seen borlas installed on gmc sierras and they sound way louder than the h3s (gm performance is made by borla). For cruising, its perfect with/out any drone, and the ride remains quiet on the inside.