There's another aspect(s) that is often overlooked, and that's what information is needed when in conjunction with what other information. In other words, how many screens.
In my Garmin G3X Touch system, I have two screens plus the GTN650 -- which is okay for textual information but too small to be useful for graphics.
Each of the 10" screens is run split screen mode, with engine instruments on the very outside of each screen, then flight instruments, then whatever "MFD" information towards the center of the airplane. This means that I have two screens available for miscellaneous displays (chart, map, traffic, and waypoint being most commonly used). And, yes, I'd like to swap out the 650 for the big-screen GTN750, but that would be a whole lot of work and expense
Lots of folks seem to run the flight instruments full screen. Especially with vertical tapes, this means that the screen real estate to either side of the tapes is wasted. (Yes, there is some minor value to peripheral vision roll cues). So why not run split screen all the time? The little inset windows are almost too small to be useful, and when you touch one to expand it, you're in split screen mode.
(I cringe when I see pictures of G3X installations where both sides are identically set up -- so much capability wasted. And until recently, Garmin marketing did not show the capabilities of their system, so they were under-selling it.)
I have run foreflight on an (early)iPad and it worked fine in the shade of the high wing Cessna, but it regularly overheated in the RV-8.
But in the RV-9A, why would I want foreflight on an iPad? I've got pretty much all I need built in. I do have foreflight on the iPhone for preflight use, and when I go IFR, the clearances I get are trivial so no need to upload them -- and I don't have the hardware on the screen to do it.
But I do run full screen when I'm shooting videos of the instruments. And full screen is marginally easier when hand-flying IFR with round gauges (they're bigger), until it's time to bring up any ancillary information, and then back to split screen.
Bottom line: there's good reason to rethink what information is used when. Don't succumb to the tendency to irrationally defend what hardware is in your airplane, figure out what really works.