I started seeing reports recently that the Garmin nuvi 3700 series will learn your preferred route, once you have deviated from a suggested route several times. I’m a bit surprised that Garmin didn’t hype this aspect of their myTrends feature, but they seem to take a low key approach and not highlight some features (like the fact that your nuvi takes into account your driving habits when calculating your ETA).
As far as I know, the 3700 series models are now the only PND’s in the US with this feature. Dash introduced something similar, and then went belly up. And Navigon announced MyRoutes, but promptly deserted the US PND market before delivering.
I wish I would have known about this when I was testing the 3700 series. I guess I have a good excuse to buy one now. Honey…