At the most basic level pixel pitch (the center-to-center distance between pixels) is perhaps the most important parameter. The other parameter is observer distance (eyeball to pixel).<p>Those two interplay and setup a situation where resolution is utterly wasted if the observer is farther than the perceptual limit.  Think of a standard Snellen chart placed at 12 meters rather than 6.<p>And so, the decision to go to 4K displays is inexorably connected with a specification of display size and viewer distance.  Ages ago IBM introduced &quot;Big Bertha&quot; probably the first 4K display.  It was about $20K.  The problem was that IBM made the display 22 inches diagonal and, at that size and resolution, you had to be 6 to 8 inches away in order to actually make use of the resolution.<p>There are other considerations but I think being able to actually use the resolution is key.<p>Personally, I prefer multiple (3) 1920x1200 monitors because it allows segmentation of your workspace.  For example, you can maximize a the video of a course or online class you are taking while you code on the middle monitor and have reference material on the third.<p>I know this will not be well received on HN but I have to say it.  The OSX UI has been grossly outdated as it pertains to large or multi monitor setups for a long, long time.  This insistance on having menu&#x27;s at the top of the monitor is rather than within the application window simply isn&#x27;t sensible.  I&#x27;ve had the experience of projecting a Mac on a 40 foot 4K theater screen.  The only way I can describe the single top menu bar experience is tiring and ridiculous.  Windows or a similarly setup Ubuntu systems with menu&#x27;s owned by the application are a dream to use on a huge multi-screen environments.  I&#x27;ve done just that with huge stadium-sized LED video walls mapped as multiple monitors to the OS.  Nothing like hqving to move a cursor across 160 feet of screen real estate to reach the menu&#x27;s to show, in no uncertain terms, that a UI is broken.