Like fuck there aren't. If you can't stand in front of a 1080p and a 4k screen (55" or even smaller) with the same demo showing on both and not see a huge difference then you are blind or have some sort or brain problem.
+1 for this. Every time someone says they can't tell the difference between 1080p and 4K, I think to myself "Just how bad is that mofos eyes???" There's a huge difference!
They had an 8K TV setup at my local Best Buy on an 18 wheeler and actually fooled most of us that it was a window to the outside of the trailer, before they told us it was a TV. It literally looked like a piece of glass to the outside. They had it turned sideways and put a wooden border around it to enhance the effect.