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its what i have used for years and years.
i personally hate voice prompts. a quick glance is all that is needed. its like looking in your mirror or at your speedo. in fact you dont need to look at your speedo with a proper sat nav as its on there. along with direction arrows, roundabout exit lanes, MW slip roads, countdown yds for turns etc.etc
ok so the proper mounts might coast you the same as your satnav but i think its worth it to have something that works.
you can also plan routes before hand using your PC then pop them into the satnav.