I actually run mine at 1920 x 1080 @ 2x so that everything is super crisp. I have a retina macbook and it was just painful looking at my other monitors.
Wouldn't a 1920 x 1080 display of the same size be more suitable then?
He can still individually address all the pixels, but targets each "pixel" to be 4 physical pixels. If the software can deal with that, like web browsers can, then you get twice as much clarity. (Try turning Chrome up to 200% default zoom. You'll notice that most websites ship assets that individually address every pixel in this new configuration. Things are the same physical size as they would be on a panel with half the resolution, but with twice the clarity. It's quite nice, even for programming.)
But now you have less content on screen than a 27" monitor.