Steve,
I was also a GM tech in a past life. Now I have a leisurely life as a tech at a local municipality.
I agree with Shiden_Kai. He is correct, and has been giving good advice on this group for a long time.
I purchased a '99 GMC Jimmy at 1 years old, and 7k miles on it. The O.E.M. pads lasted 57k miles, with little to no squeal, and they stopped the truck on a dime. The new pads cost me $75 wholesale at GM. I still get a discount because I know the people at the dealership. Your price would be higher for O.E.M. pads.
8 years ago I had an '87 Pontiac Bonneville. I installed some Wagner brake pads on it. A week later, coming home from work, I was cut off by another vehicle on an interstate. I mashed the pedal down and the car kept rolling. My Bonneville didn't have anti-lock brakes. The brakes didn't even chirp. If I didn't pull onto the shoulder, I would have rear-ended that guy.
I purchased the O.E.M. pads, and man what a difference. The car stopped on a dime.
In conclusion, ... brake pad compounds vary by manufacturer.
There are 4 things that I deem very important as far as mechanical safety. Brakes, suspension, steering, and tires. These are the things that give you dirrectional control and stopping power. If you want to skimp on these, you take your life, and your family's, into your hands.
GMdude