I do not subscribe to XM any longer; not that it wasn't ok, but many of my trips are shorter, and I turn anything off that makes noise and enjoy the quiet. I sometimes just like to hear the engine working.
I do however have four vehicles currently with OnStar safe & sound activated. I probably will continue this on all except my Silverado. The Silverado is too old to work with the OnStar RemoteLink app for the smartphone. The RemoteLink is quite usefull for our Equinox and the wifes Sonic as the remote start can be activated via the smartphone at any location or distance, and verifies activation on the phones screen. The ability to lock and unlock the doors from the phone is another feature that sounds silly, but more than once I have went into a store, not sure if I locked my vehicle. Instead of worrying about it or walking back within keyfob range; I simply pull out my phone and lock the doors. It verifies door lock activation on the phones screen. Along with the diagnostic reports, tire pressure monitoring, crash response, emergency support, stolen vehicle recovery and other features, I still enjoy this service. Is it necessary? No. It is a mix between novelty, convenience, and safety; and with a typical cost after negotiations of about $149 per year; I still think it is good for my purposes.
Our Forum brother Laborsmith, and some others, have an opposing opinion of the OnStar service, and I respect their views and opinions, and also agree with most of the concerns about compromised privacy using this service; but for me, the good overshadows the bad.
Papasonic