High DPI. It makes text so more easy to read. For me personally I also wouldn't have too much use for ultrawide, since I run most apps in fullscreen mode and do

High DPI. It makes text so more easy to read. For me personally I also wouldn't have too much use for ultrawide, since I run most apps in fullscreen mode and don't like turning my head while working. High quality 4k/27" are most likely the sweet spot right now and works good with 175-200% scaling (on MacOS I use 200% and decrease font sizes in some apps - on Windows 175% works ok). 5k/27" would be the ideal thing, but there are barely models available, and the requirements for Thunderbolt 3 makes them less interoperable. I'm waiting for higher resolution screens to show up with new Displayport and HDMI revisions and would upgrade then.