add-on gps navigation

[sixto]

Does anyone have experiece to share on add-on GPS navigation devices? I'd like to get one for the family to use but I haven't found idiot-friendly information on the web. magellangps.com and garmin.com have detail specs, but don't help me decide whether product A or product B gets me the feature set I need. I'm also confused about what maps comes in the units and what has to be downloaded from the maps on CD.

I imagine the most important feature is address to address mapping similar to what's offered in yahoo maps or mapquest. Beyond that I'd like to be able to fit the SF Bay Area (say Monterey to Silverado) into memory and not have to sacrifice it to augment with SoCal and Tahoe from time to time.

I'd also prefer a portable unit over a hardwired unit with it's own CD drive or changer.

Any insight is appreciated.

Thanks,
Sixto
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