I think he is not making the most of these fantastic instruments.

I use only 750 for the navigation, I read about people using one 750,

for navigation and other for checklist, and some one the 650 keep it for TICAS!

And which configuration do you fly with?

In real life I use my 750 for moving map and ADSB traffic.

 Enroute the 650 is usually on nearest airport and approach I change to default nav page.