The 396/496 gives you XM-WX capability, which you can also add to your '430.
If you already have the weather capability in your '430, I'd opt for a
lower cost Garmin, like a 196, to provide backup GPS and, most critically, a
backup for the DG (by placing the 196 in the HSI mode). Either way, I'd
also add an electric backup AI

-Elliott Drucker