I have a G3X (non-touch) with a GTN-650. I only use the 650 to input my flight plan and to select instrument approach procedures. I have a couple user data fields on the screen that I like to reference that aren't available on the G3x. Aside from that, those are basically the only two interactions I have with the 650's touchscreen; everything else is done via input to the G3X.
The 750's full screen keyboard would be nice, but not really a necessity for me. And given that Foreflight and Garmin Pilot can now transfer flight plans to your 650/750 via FlightStream, I'm not sure that the bigger screen is worth the extra $$$.
I have AFS 5600s & GTN-650. The moving map on the 5600 has good screen real estate, making it easy to view. The 750 has the advantage of using a full keyboard & decent screen real estate. The cost for maps & plates from Garmin is high relative to others, e.g., Seattle Avionics.
Cost for AFS (or others) and a 650 is lower than the combined cost for all Garmin. In the end it may come to a matter of personal preference and familiarity.
The cost for IFR updates is high period for any IFR Navigator. You can thank Jeppessen for that...
The cost for a year of updates for the G3X is $149.99.
Apple's to apples, the Garmin G3X Touch system package pricing is similar or even a couple hundred less than the competition. Not to mention that most of the time they offer deals when the GTN is packaged with the G3X system.
OP:
If money is no problem, go with the 750. If you have a budget, go with the 650. I have a 2 screen Touch panel and a 650 and they work beautifully together. It is like cheating!
Thanks,No sir.
When you add the IFR Navigator to the mix, the price goes way up. They have a Pilot Packs available that do combine both in one subscription.
What I do is only update the Navigation database on the GTN650 as needed and keep the current maps charts and plates on the G3X updated. Works out better for my situation.
If you have a GTN750, and you want charts and plates on that big beautiful screen, the way I do it won't work.