I won't disagree that there is a visible difference between 4K and HD
if everything else is working as it should.
My first 4K TV went back because, although it had 4 USB ports only 1 of them was available to play back 4K content and then only in a very 'flaky' way. It also refused to stream any video off my network. I got nearly £100 refund and bought a Sony instead and that plays back 4K very reliably.
If your source material is good quality, well exposed and focused (
that's a whole different story) then once again, I agree. At the moment my source material, whilst it is in 4K looks just as good if not better rendered to HD. My eyesight is no longer what it used to be in fact that goes for my hearing as well. When it comes to appreciating the look and sound of things I've been left in no doubt by friends and family that my preferences are not the norm. My assessment of the final results that I achieve is, I admit, very subjective.
Although file sizes are no longer as important as they used to be and as I said, the smaller files are a consideration for me.
Oh alright - Go on then - 4K is better than UHD
.