When I bought my Silverado, it came with 6 months of OnStar and my wife bought minutes for the phone part of it. The phone part worked great for me. Never had any issues with dropped calls. No one ever complained about being able to hear me and every thing sounded loud and clear in the truck. I did drop OnStar after the 6 months was up. I didn't use it often enough to justify paying for it. No complaints for me other than the price.