So the sound and signal quality aren't any better than FM? Also, with it being satellite, I would think that you should be able to pick it up anywhere, just like you should be able to use your GPS anywhere.
Let me re-phrase this.
The sound and signal quality are about as good as you could expect out of a motorcycle sound system.
In your house and car you could expect near CD quality out of an XM receiver, with no static. Typically, with XM, if the signal is weak it just goes out, unlike listening to an FM receiver.
XM and Sirius use only one satellite each as far as I know. GPS is a US government run program, called NAVSTAR GPS, utilizing 30 satellites. The system uses 24 and usually has 6 “spare” satellites (there is a new GPS satellite that what put up a couple years ago the is causing havoc with many older GPS units).
You only need three to get the most basic fix and at least 4 to get a “3D” fix (altitude).
Typical consumer GPS units will “see” anywhere from 4 – 12 satellites at a time. Many GPS units have a screen that will show you the sats in view in real time.
So – you only need 4 sats for a “fix. You GPS will typically have in view 8-12 sats.
So that is why your GPS will work better then your 1 satellite XM. It is not unusual in my area to ride down one particular highway that has no tree coverage and to have my XM go in and out.
BTW, it may be hard to believe. But the US government named “NAVSTAR” of the GPS system (Global Positioning System) is NOT an acronym!