Install took about an hour. Getting the center console apart is a little bit of a pain. There's a good thread that has a lot of pictures on how to get the console apart for a different mod. I used that as a guide for disassembly: http://www.camaro5.com/forums/showthread.php?t=77662
Once I had it disassembled, the Yaw-Sensor was bolted to the floor to the left of the hand-brake. I just removed and replaced.
As for truly knowing it only affects HSA, I suppose more time and data will be needed. From my observations, that the car starts with no warning lights or error messages (unlike the fuse-pull method I tried before). Hill Assist message never appears, and HSA never activates. Traction Control still kicks in under aggressive throttle, and ABS still works.
Thoroughly testing Stabilitrak would require somewhere other than the street I think. Maybe one of the track-regulars could give it a go, and post their findings.
Oh, and OzzySS, I'm still curious about the method you used to defeat HSA along with other electronic nannies as well.