I've been looking at this GPS unit, the Dash Express.
It looks pretty cool. It has internet connectivity through cellular and wifi networks. So, instead of having a static list of restaurants or other area points of interest... it can search. Maps can be automatically updated. Traffic heat maps are on a whole new dimension.
It also give three different route choices, their mileage and expected time. That would be great for me, because I often like to go a slightly different way in order to accomplish something along the way (gotta combine those trips, you know!).
But... using one is the best way to know about one...
And if you aren't, go wander around the site and see what you think.