Hi Tim,
I'm curious how you are using 4 devices in the airplane at once ... Since I don't have a GPS navigator, I was thinking that I would have different pages up with different info, such as:
- Dedicated approach plate
- Dedicated EFIS with highway in the sky
- Enroute chart
- Weather for route and destination
Your G300 already does that for you, but your iPad gives you one or two more screens of situational awareness. But even if I only have a couple of devices open, I might want to have one or two backups available in the headset bag with current Charts and my Instrument Groups.
I think the problem comes in when you make changes on one device (in the air) that don't automatically get made on the other three ... I would make changes to the flight plan in one unit then use the built-in utility to share that flight plan to the other (up to 3) siblings.