Yep... I believe that I have heard most of what you all have said here before.
I wish that using the headset with my cell phone was all that was in question for me. I will miss having that extra power in signal with the Onstar system. I will miss having Onstar to help me out in a pinch when I get turned around on one of my many trips. I will miss knowing it willl notify someone if I wreck and air bags deploy.
I hope starting this discussion has helped some folks with their decisions and acting upon options. With my 01, I have no options. You folks with newer cars have the chance to utilize a cool feature for a long time to come.