You idea of "spitting distance" and mine are worlds apart. When I am working in Photoshop, for me there is no "spitting distance of each other in the proverbial sense"
Or perhaps I've just gotten lucky with my set of panels. You're welcome to come by and have a look for yourself, and if you have a spectrometer, see if the differences aren't, as I suspect, less than an average DeltaE of 2.
You prove my point when you say your iPad is not at 6504k, it was a bit off.
You're right that out of the four devices I've compared side-by-side, there is one outlier, which after all is 25%. However, if I recall, the iPad Air came out prior to Apple calibrating displays from the factory.
"Night Shift wasn't enabled, right?" LOL!
I really didn't mean for that to be condescending, and I'm sorry if you took it that way. As I said we can all make stupid mistakes and I've made my fair share. I wasn't in any way trying to imply that you'd consciously miss it or anything.
PS. I do semi-pro colour grading for film, so I do in fact pay quite close attention to this stuff. I realise you also mentioned doing work with Photoshop, so my point is merely that we shouldn't question each others' merits in terms of judgement, since we have no idea of the other person's abilities, uses and the like. As a starting point, assuming competence is preferred I find. Although it may often come with disappointments, it avoids unnecessary negativity and potential insults.
When I say "within spitting distance", I mean barely perceivable by the human eye, i.e. less than a DeltaE of 2.