I've been going back and forth on this subject for the last week or so. I saved up the cash to invest in whichever system I would like - between XM, or high speed cellular data, etc.
Here are the three data coverage maps for the major providers:
Cingular:
Sprint (dark green is in network, light green is roaming):
Verizon (light yellow is in network, dark is roaming):
No one service seems to be comprehensive in the plains ... you can have Sprint and be well off in Texas, but have lousy service in Nebraska. Or have Cingular, with outstanding service in Oklahoma, and virtually non-existent service in Iowa and Nebraska. Verizon and Sprint still seem to me to have the edge on across-the-map coverage at this point.
Next I've been considering a new phone - thinking of a smartphone. Would like one with an HTML viewer so I can download radar right to the phone, rather than worrying about linking to the laptop, which will be used for GPS mapping. If the map issue is confusing, the phone issue is ten times moreso. One phone will have an html viewer, but you can't use it to double as a modem, etc. Some phones utilize the new MS Windows Mobile 5.0 OS, while others use Palm or proprietary OS.
It just seems like - I can use a cell service with Swift and be able to use the service for a variety of things all year long, where XM is limited to chasing only - and represents a huge startup investment. I've been chasing with the eyes-only method for so long now, I really don't know if it's a good idea for me to try to become techno-reliant at this point, even though the option is certainly there. I was going back and forth on this all night last night.