I used a 27@1440[1] for years, and for a long time I thought it was the perfect size and resolution for me (and of course I love HiDPI, a 27@2880 would be great too; but I actually prefer to keep a low DPI screen for web/visual work so I can see what a lot of the world sees).
On a lark, last year I bought a 42.5@2160 (4k)[2], with the intention of using it primarily for tv/movies at that size, not knowing whether it would be suitable for work. But at 1x it’s nearly the same DPI as the 27@1440 so I have it a shot.
And at first the only way I could describe it was “comically large” and “probably a mistake”. For work, I only used the bottom half of the screen.
After a move, I changed my setup a bit, with the comically large screen set lower on my desk. This improved my viewing angle so much that I’m able to use the full vertical range of the screen (though it’s still so side that I treat the rightmost 20% or so as mostly a dead zone). Now I don’t know how I’d work with a smaller screen. That much vertical space is a godsend for dev, leaving tons of room for editor & debugger, or browser & dev tools.
It’s probably not for everyone, but for folks with a little disposable income and who might imagine finding the 27@1440 a little cramped, I recommend giving it a try!
[1]: Samsung S27A850D, with a PLS panel, which at the time was an interesting IPS alternative for me. I do realize that a high quality panel somewhat undermines my “see what the world sees” goal, but frankly my eyes and brain hate TN panels.
[2]: LG 43UD79-B, this time IPS, and I honestly can’t tell a difference in the panel quality.