Study: Two Monitors or One Ultrawide
How about two vertical monitors? I use a laptop and normally also have connected two 27″ monitors, both vertically oriented, above it. There are certain code tasks that really benefit from the increased height of vertical orientation; as an example, last week I was doing some substantial rebasing, and the increased vertical height in a four-way diff was invaluable. Most of the time I find I’m actually using at most one of the external displays, but it’s definitely still common to get practical value out of both of them. Referring to web pages or other documents on vertical screens is also normally better—mostly normally because they’re half the DPI of my laptop display.  ┌────┬────┐
  │    │    │
  │    │    │
  │    │    │
  └──┬─┴──┬─┘
     │    │
     └────┘

(The slight off-centring of the laptop in this diagram is also curiously realistic; early on, a couple of years ago, I had it centred; but a few weeks ago I looked closely at where it had ended up, and found that I consistently placed the laptop definitely right of centre, and favour the right-hand monitor to the left.)A few others in the company use one or more vertical screens too. Those of us who do, certainly like the increased vertical space.Quality of window management is also going to be an important factor: of the two main OSes: Windows is good at simple window-per-screen and two-tiled-windows-per-screen arrangements; macOS is fairly weak, being more inclined to manually accomplishing it. (I’m on Windows for now, but I’m planning on trying Arch Linux, which I previously used, on my Surface Book, as it’s now probably good enough to work with. With Sway (i3 clone for Wayland), its handling of such a screen arrangement will be superb.)