For the record, I don’t quite regret it, but software UIs have largely not caught up to it.
I know people who swear by it (size and res), but upon asking, they tend to all be on the text or photoshop heavy side of things, or into gaming.
For those, it’s great.
When the Widgets in the UI matter little and the contents of the main viewport, be it a text editor in an IDE or your canvas, are everything, it’s great.
The problem arises with interfaces that are widget heavy and aren’t scalable.
If clicking the “frame” part of the UI or fixed sized items is a must, it can get painful very quickly.
IE: in ZBrush the axis icons by some sliders, which you can’t work around with keybindings, are literally just over a mm tall.
In games or UIs where paragraph text is rendered at a fixed size even with perfect eyesight and relaxing glasses it can get straining after a while. And so on.
If UIs scaled properly, like they do in some softwares or like windows/linux/OS-X do with the iconsize and text options, it’d be dandy, but most softwares simply don’t.
If you’re on a budget, and the choice is between two 24s and one 27, two 24s any day of the year, without hesitation.
If you don’t use ZBrush and don’t need to click on icons and widgets that will inevitably be rendered microscopically, and you mostly work single task off the one viewport (painting), then one 27 COULD be considered, but goes out the window when the option of having reference and browsing on the second monitor is so convenient in a dual 24 setup.