I bought XM radio service just before Christmas (December 2003), so my
experience is not even a year long. However, in my case, getting XM
changed my radio listening habits around 98%.

The *only* time I have my radio on (regular) FM is Saturday mornings
at 10:00am for NPR's Car Talk. With that exception, my XM is always
in use. Once XM adds channel 133 in September (Public Radio stuff) I
may not even need to do that.

If you take n=100 meaning the time that I am listening to the XM
signal, I would guess about 40% of the time I am listening to XM talk
stations (usually CSPAN or the comedy channels, occasionally CNBC and
CNN, every now and then Fox). The remaining 60% is music, and that
varies based on my mood and the time of day.

Absolutely the #1 selling point for me was reception *everywhere*.
MountAINS OF Pennsylvania, coast of North Carolina, never any fadeouts
or other reception issues. (Well, I shouldn't say NEVER. On some
roads, like the Pa. TUrnpike where there are hills right next to the
road, the satellite can't see the antenna and I get occasional
dropout. But almost perfect, and far better than AM or FM.

Since PBS went commercial, I get more for my $10/month on XM than I
ever did with a membership to a public radio station.
--
Ted Koppel