Doug

If you define GPS functionality as the ability to go enroute and do
approaches, only the Garmin 480 has functionality over the 430, 530,
KIng series (90, 89) or any of the other ones that have enroute, and
approach capability.

If you define functionality as something else, then there is a
difference.

To me, the biggest difference would be being able to get the Nexrad
data off the XMradio band. But of course you have to pay the
subscription costs.