However, all else is rarely equal, and 4K TVs now have lots of other features and technology that make them just better (prettier) buys in general.
[1] http://s3.carltonbale.com/resolution_chart.html
I'm honestly wondering if I'm an outlier and may have better than 20/20 vision. I would think it's pretty rare, but I have had people comment on my vision before. I work on a 17" 4k laptop screen with tiny text no prob.