But I wanted to poll this. It would be nice to pin this thread as feedback for @Ford Motor Company. TCCustoms recently put out a video of the mid-cycle refresh of the Expedition and pointed out that it is using the same cabin set as the F-150. So the XLT they were previewing had the 12" (I believe it also gets the 15.5" at the upper trims). This got me thinking that if Ford had more feedback maybe they'd decide to make the 12" available at the upper trims.
One of the comments I've seen reviewers bring up is that the 12" provides a better camera size for backing up, trailer, etc.
I think if I had the option, I would pick the 12" screen. I like hard buttons for certain features. When I test drove a Pro, I liked having the camera button right there at the top. Same with Temp control. A year with the mach e, it does get irritating to "wait" any amount of time for the screen to load to turn off or on the HVAC system (part of this is because the Fordpass app is lacking).
I do like the 15.5" screen. This is mainly because I like the largest amount of room for maps (I think vertical is better than horizontal, especially in 3D view). And while the Lightning 15.5" is better integrated into the dash than the Mach E, it isn't better looking than the 12" to me. This all seems like the option should be there because it'll be preference for what you are using it for. I think those that tow/haul or offroad for camping more often would want the 12" while I think I would still get the 15.5" inch because of how often I'm using maps.