Also a big fan of Garmin's NUVI series because of their ability to 'learn' from your driving behaviour over time. For example, my NUVI has given up trying to send me down the M3 to Dorset now it 'knows' I prefer the A3/A31. Also (and this takes longer) it will adjust its ETA calculations once it accumulates data on how you drive in relation to speed limits for different categories of road. So the unit in the 4/4 knows that my motorway speed - top always down of course - will be around 60mph (rather than the 70+ it will assume on factory settings).
Garmin rather hide their light under a bushel in this regard as there is nothing I could find in the manual, but if you are curious then do a factory re-set of a 'trained' unit between two back-to-back journeys and you will see what I mean.
