Buying a new Silverado-Questions

So...I am going to buy a new Silverado (2005) in the next couple of days because of this great employee discount they have going on now. I am thinking about a 1500 Crew Cab LT with the video. How do you like the onstar system? How is the coverage? I am planning to travel from CA to VA and I am wondering if there is really emergency service all over or will there be gaps?

What other options are good to have?

The red button on the On Star will work whether you subscribe or not. What On Star provides with subscription is the "You set off air bag, they call you." You can press the red emergancy button at any time and they will answer, no question asked. I bought mine used so I have never had the On Star hooked up. In two weeks I am traveling 5K from Tx to Mt and back with my 6 yr old twins. I think the $17 for one month subscription will come in handy incase I get incapasitated and they need help, God help the person who thinks about stealing my truck, or the "I get locked out."

Find out if the new system On Star has in that truck is digital or the old style analog. Can the system switch back and forth as needed?