You didn't mention the model numbers on the 2 nor the content running on both of them is what concerns me, or if they were running identical content & identical lighting, source (video or loop), how you got the exact 12ft measurement or if that is a ballpark guess etc.
With me being a consumer in the market I of course wouldn't want to simply take word of mouth without the facts, spend $8k and find myself to have made a mistake, and I wouldn't want anyone on the forums to be misinformed and it be a determining factor in their next purchase without knowing this is completely solid & detailed information either. That is why I am asking in such detail.
Were they both running identical 4K films with an HDMI splitter splitting off into the 2, and down converting to 1080 for the 1080 set, what models were the 2 sets (so I know for fact they are identical technology besides resolution), and what 4K film was being played (or 1080 film being up converted)? Or were you watching a loop? I'm curious of what would say... Mastered in 4K "Robocop" on a BluRay look like if it were up converted via 4K TV (and being displayed on identical 2K set), or the opposite which is taking True 4K content and down converting for the 1080 set, because if 2 different sources were being used from 2 differently mastered copies of video, the truth is still unclear.
My thoughts as a person who has never seen 2 identical tech TVs (2 identical FALD panels is what I would like to see compared):
Double the resolution (tho it's said to be 4x HD) means the pixels are half the size, and this is where I get confused as to how distances wouldn't have to be halved for 4K view. Can you give an opinion on when the 4K set is out of range, and have you confirmed the percentage in distance which is the true viewing distances from both identical tech 2K & 4K sets? I would be curious if someone measured the approximate differences when looking at the 2 identical sets.
I have a mount in my wall which is approximately double the height (circular) as the door knob on the door I'm looking at right now. When standing back a bit the height of the circular handle is around 6mm & the bumper is 12mm.
It's hard to understand, knowing that in fact pixels are a physical measurement, and could even be compared in perspective of standing back from a Lotus Elise next to a truck which approximately double the length. I guess I simply don't understand how a physical measurement can be manipulated into anything than exactly what the physical measurement is stated, where 4K is a pixel measurement of half the size. Since it is a physical measurement it is kind of like trying to be convinced that $5k is not half of $10k, but money is a calculation as is a a physical measurement of dimensions, and I know how these electronics companies play games to try to get consumers to buy their product.
I will give the mentioned forums a view, but I know there are biased opinions throughout, where as I am looking for a direct, fully detailed non-biased answer.