decided to just ask Walt, the owner of ADCMobile and he was kind enough to copy me on an email chain of a customer with an '06 Impala SS that bought this product.
He lost the chime to the on/off of the automatic light system and use of his steering wheel controls, (and in March of 13 there was no expected fix, turns out the differences were in the CAN codes that talk to the ECU and radio since there was a motor change in '07) BUT other than volume and track change the hands-free wouldn't work anyhow with the radio Bluetooth. I am weighing the pros and cons ATM. Plus found the system on Amazon and Best Buy for $599 and $699 respectively. As far as the antennae, it comes with it's own GPS one that you can mount on something metal in the dash board (it has magnets)