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Frangible said:
... But there's a lot to be said about something that's self-contained and a lot more usable while driving.
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The PDA touch screen is perfect for tapping whilst driving and TomTom has some large sized [screen] buttons designed to make tapping easy. Plus the 3d effect of navigator is much better than a 2d view when driving and makes good use of the larger vertical aspect of the screen.
For instance, when driving if you come to a traffic jam you just touch the screen and this brings up the options, road block is a big clear icon, touch that and you have more large icons avoid road, avoid next mile etc etc, tap one of those and the navigation map is re-displaid and route recalculated.
All this is done quickly and with minimum time to take your eyes from the road. Its better than the stand alone units for this.
Depending on your dash layout a separate unit and GPS reciever can give more options for intalling, and better reception. Some coated windscreens require specific locating of the GPS reciever
The PDA is easier to remove to prevent any tempting break-ins, and cables are hidded just the same as a dedicated unit.
The only downside is that once you've used (or even seen one in use) you don't want to drive anywhere without it!
BTW, Aldi have a Medion PDA unit on sale at frequent intervals and this is the cheapest setup you can get, and it works straight out of the box with no need for a PC. Watch out for this.