Jollyrog you have a PM.
I mounted a 496 in my TB20 yoke, and connected its audio output to a spare intercom input, and if the AUX button is pressed (which it always is) I get audio terrain warnings.
These warnings are one major difference between the 496 and the 296, but Garmin have gone to a great length to make the differences hard to establish, to prop up the sizeable price difference between the two.