IFD 540 vs 750 Xi

[SoCal 182 Driver]

Not a damn thing. There is no reason to rip out a working navigator of the caliber of the GNS series in this day and age, when you can simply install a FlightStream 210 and an iPad and get an awful lot of the functionality of the new units.

And the GNS WAAS series is not "obsolete" yet. LORAN is obsolete. The GNS series is merely elderly.

I would sell my GTN 750 and exchange it for a 750Xi, but only because the installation is pretty much a slide-in and the new unit would be configured, updated, and ready in a couple of hours in the shop at most. I do love the 750, though, and would be happy with it for many years to come. I just bought it in the tail end of the product cycle. And if the install of the Xi wasn't so trivial, there's no way I would consider replacing the (non-Xi) 750.

Likewise, if I'd had a working GNS WAAS navigator when we did the ADS-B upgrade, I'd have left it in place or at worst moved it to #2.

Would I install a used GNS today? Nope... But if there's already one in your panel, there's no compelling reason to ditch it just yet. And I'm one of the biggest gadget freaks I know.

Respectfully, I disagree. I have flown behind both the GNS530W and the IFD540. Hands down the 540 is a better unit. More intuitive and much easier to use. More user options. Incredible screen resolution. Terrain warning. Synthetic vision. I recall attending an Avidyne IFD webinar, and the presenter inputted a route with hold and an approach. He commented that it took him about 60 knob twists or button pushes to input the route into the 540, and over 400 to input the same route into a 530W. Now, a lot of that can be alleviated by a Flightstream and an iPad, true, but it terms of the box itself, IMHO the IFD540 is a far better unit. YMMV.