I use a 1440p display at 100% and a 4k display at 175% on Windows and it works fine. The only bug that I see is that if a window is spanned across two monitors, it picks the scaling based on which monitor contains more of the window. I'm not even sure that's a bug, it's just how it has to be done. (My first mixed DPI setup was actually on ChromeOS. That got around the issue by not letting a window span monitors. Actually a somewhat elegant workaround, since it didn't let you do that before HiDPI support ;)
Windows and the applications I use even handle the different refresh rates of my monitors pretty well. I have a 165Hz main monitor and a normal 60Hz monitor. Apps are aware of the framerate differences when I move them around.
It wasn't always good, but as time goes forward applications and Windows itself handles HiDPI better and better.
(FWIW, I haven't had any problems on Ubuntu... except that letting the monitors go into power saving mode resets the display scaling override. That was with 18.10, though. I use an Ubuntu VM under Hyper-V now... begrudgingly.)
Having said that, I am not a GUI power user by any means. On Linux, all I ever use are a browser, terminal, and Emacs. On Windows, I use CAD software and games (and a browser, terminal, and Emacs). It all works well enough for me.
Windows and the applications I use even handle the different refresh rates of my monitors pretty well. I have a 165Hz main monitor and a normal 60Hz monitor. Apps are aware of the framerate differences when I move them around.
It wasn't always good, but as time goes forward applications and Windows itself handles HiDPI better and better.
(FWIW, I haven't had any problems on Ubuntu... except that letting the monitors go into power saving mode resets the display scaling override. That was with 18.10, though. I use an Ubuntu VM under Hyper-V now... begrudgingly.)
Having said that, I am not a GUI power user by any means. On Linux, all I ever use are a browser, terminal, and Emacs. On Windows, I use CAD software and games (and a browser, terminal, and Emacs). It all works well enough for me.