the only difference is that its smaller and you can carry it around easier than conventional portable units. you dont NEED it if you dont use GPS much, if you have it in your car. you STILL need mapping software whereas standalone units do not (they have it preloaded).

with the freedom you have the ..ahem.. freedom
to pair it with most BT enabled phones and go walking around town with ease.

i have GPS in the cars but i purchased this anyway just to have. i keep it on a lanyard and just throw it over the rearview mirror as i have more than one car and putting it on one key ring is not convenient for me..