I've just bought this pair.  Great products of course! 😊

It would be easy to fall back on the 530 alone but I'd like to see how to use the two units to comlement each other.

I selected 500 rather than the 530 to take out the radios and give a larger display.  I've enabled cross-fill.

What do others use the extra 430 for please. I'm sure it is far more than a good looking back up unit?

 Display the map on one and the flight plan listing on the other...  Or user the user fields on the two map displays, a map on each, and define the user fields in the four corners of the maps to display different data...  Or use the second GNS to lookup frequencies for your destination.....  Or stay with ATC on the primary but tune in ATIS on COM2 with the other.  Or use the maps on both but at different range (distance) settings, one to show just as far as the next turn on your flight plan, but the other perhaps tighter in so you can better watch surrounding traffic.

The possibilities are endless.....

Here is another tip.  With each RXP GPS product you get (2) gauges.  ex. you get GSN 430_1 and GNS 430_2.  They are separate from each other.  You can store a totally different set of flight plans in each, yet still crossfill. What I do is store flight plans for aircraft I can fly farther and higher in _1, and flight plans for lower altitude, shorter range aircraft in _2.  When a particular aircraft's panel can only accommodate one GNS I pick accordingly.  When I can fit two then I have both sets of flight plans available and can crossfill either direction.  Just remember you can only use one _1 and one _2 in a single aircraft.  Can be 430_1 and 430_2, or 430_1 and 530_2, or 430_2 and 530_1, etc.