It's weird that the rule of thumb was always that no average person could see the difference between 720p and 1080p on an LCD screen that was under 40" (it was all marketing B.S.), and yet here we now have super high res screens that are a mere 13" and everyone is losing the minds at how "amazing" they are.
Sooo, what happened between then and now? Is it that the resolution actually has nothing to do with it (is just a number that people can relate to for marketing purposes) and that it's the technology of the display itself that makes the screen look good? Or, what?