-
Agreed, *plus* with a portable e.g. Garmin you can do stuff like import POI databases etc. - I have one for traffic cameras since MD and DC are traffic camera hellholes and I occasionally have to go there. Now it'd be nice to have something integrated into the dashboard for a more finished look, but really, that doesn't outweigh all the good arguments in favor of a portable.
At some point smart phones are going to get good enough that you won't even need a separate GPS unit, just a windshield bracket and car charger for your phone. they're almost there now.
nate