Ctowner said:
IMO I would go with a portable gps over in dash unit because if your car ever breaks down you can bring it with you in a rental, if you are taking a road trip in a friend' scar you can bring it along, etc. The tomtom one you can even use while walking around on foot. With an in dash unit there are no other options.
you have valid points and those are some of the reasons why I love my portable unit. But at the same time, there are some things about the built in nav systems that are also better than the portable units.
The biggest advantage the built in navigation systems have over the portable units is the amount of POI (point of interests) stored. There are many places that my nuvi 660 cannot find that frustrates me, because some of these places are big and well known. The best example I have is Cerritos Auto Square. If you live in SoCal, chances are you know or have heard about Cerritos Auto Square as its one of the largest auto mall. To the nuvi, this place doesn't exist and on the map, it doesn't exist either other than a large, empty space.
Also, on the nuvi sometimes when you search for a POI it takes forever for the results to come up. On the other hand, with built in navigation sometimes a lot of the work is done on the fly. IE, if you're looking up something on Washington street, as you type in each letter of the word w-a-s-h-i-n-g-t-o-n, it automatically eliminates letters that the system knows will not be in any of the streets in its database. So if you typed in the letter W, the system will automatically not let you type in a Q after it, because no street is going to start with WQ.
I also find the voices on built in navigation systems to be a lot more pleasant and realistic. On the portable units, the voices in general sound robotic or computerized. I also hate how mine says "recalculating" every time I don't follow its instruction. With some built in navs, it just spits out the next direction without telling you it's recalculating. It feels much more human. With the newer built in navigations, some also take into consideration the street you prefer and calculates that into the route. Some systems bother you constantly just because you'd rather stay on street A than street B, even though you know both streets can get you to the same place.
Both type of GPS has their strengths and weaknesses. For most people, I would say a portable unit is better. But if you want the best navigation possible and you don't care about portability from one car to another, then a built in nav system will be better because not only will you have the most amount of POIs stored in the database, it will also be completely integrated. Who wouldn't want to have one system that completely controls their nav, radio, sat, and iPod in one?
My advice though for anyone looking into getting a portable unit is to get one with Bluetooth. This feature is worth the price alone. You can purchase seperate bluetooth systems for a couple hundred bucks that won't even have the features the built in bluetooth on your portable GPS will have. I can do a search for a restaurant, and once the system finds it I can have it place a call to book a reservation or something. I've found the Bluetooth feature to be really handy.