Because my Surface Pro 4 can run 3 1920x1200 monitors just fine (I'm partial to a -|- setup (dontjudgeme)). The dock really makes it, no question. My monitors stands stay bolted to the desk and everything's cabled together, but I'm personally not tethered.
Best of both worlds, to me at least. (Except for when I need to do something irresponsibly inefficient like run three VMs and full screen video at once... which will work, but not be great.)
Best of both worlds, to me at least. (Except for when I need to do something irresponsibly inefficient like run three VMs and full screen video at once... which will work, but not be great.)