We just got back from our Thanksgiving trip. We used Google Maps/Navigation down and back. It just up-and-quit about 4 times, especially on the way back. Power off and back on seemed to be required to get it working again. I don't have many data points before the KitKat upgrade, but I had never seen that before.
I'm not worried that it's unfixable, but it is a bit disconcerting. :-/
Caution might be in order if you haven't upgraded to KitKat yet.
YMMV, of course.
Cheers,
Scott.