It's actually quite OK, with just some minor annoyances. Three scenarios for my use case:
1. Use the laptop screen only. This is easy. Just change the DPI value in my ~/.Xprofile and everything is solved.
2. Use external monitors only. Just use the default DPI value.
3. Use laptop screen in combination with external monitors. This doesn't occur hat often. But when I have to do this, there are also some ways to make it work. You can refer to https://wiki.archlinux.org/index.php/HiDPI for some reference.
- The first way is to increase the DPI in ~/.Xprofile and actually scale up the external monitor instead. I don't like this method since the external monitor just looks blurry for some reason.
- Or you can keep the DPI and downscale your internal monitor.
- Or, and this is what I do currently, use apps that support manually setting DPI in their settings, e.g. Firefox and Thunderbird, on the laptop display. You can also manually change font sizes of apps that you're going to use on the laptop display. This is a bit inconvenient but the display result will look totally natural.