I have a Verizon EV-DO card. With a Verizon voice plan, the unlimited data plan for the wireless card is $60/month.
When I'm in an area with EV-DO service (aka Verizon BroadbandAccess), the speeds usually range from 500Kbps to 1Mbps. I have gotten as high as 1.8Mbps. Comparable to slower DSL or the actual throughput on some cable modems.
When I'm not in an EV-DO area, I still can almost always get reception for Verizon's NationalAccess. Speed on that runs about 3 times faster than dialup. Usually around 150Kbps. And I get that even when out in the STICKS!
If you're concerned about multiple computers, you *can* setup your home/RV network so that all your computers share the connection through one laptop with the aircard in it.
If you decide to go for an aircard solution, my research (about 2 months ago) led me to these conclusions:
The Kyocera KPC650 is THE aircard to get. It will cost a little more than a Verizon-branded card, but it will get reception where others won't.
Verizon has better coverage than Sprint in major metro areas. But Sprint has EV-DO coverage in more smaller, out-of-the-way places. You just have to look at their coverage maps and decide which is better for you.
Verizon is $20 per month cheaper than Sprint, if you also have a voice plan. At least, it was 2 months ago. Of course, Sprint could also now be on board with the $60/month deal for voice subscribers.
And I guess I should point out the obvious, which is that you can use an aircard while driving. Well, your passenger(s) can, anyway. /ubbthreads/images/graemlins/shocked.gif It sounds like maybe that is not true for those satellite options.