I bought an XM module and a lifetime subscription when XM and Sirius were separate. When they merged I got both. I have cradles and antennas in my daily driver, toad, MH and a boom box. The biggest benefit is not having to hunt down a different station every 40 or 50 miles when traveling. I'm also lucky that my home town of Cincinnati has WLW, one of the clear channel stations that's broadcast on XM so I can listen to the hometown news wherever I am. The only reception problems I've run into is about half way thru Canada on my way to Alaska, due to the curvature of the earth, and strangely, on I-64 near Colonial Williamsburg, Va. That road is lined with very tall pine trees. According to XM, its due to the sap in the pine needles that blocks the signal.
