Some MS fonts look ugly
The issue is affects Calibri and Cambria (might affect other fonts I haven't tested all of them). At certain resolutions and font size the they appear "blocky" (e.g. font size <15 @ 1080p 100% scaling). Googling around I found it can be fixed by disabling embedded bitmaps. Adding the following:
<match target="font" >
<edit name="embeddedbitmap" mode="assign">
<bool>false</bool>
</edit>
</match>
to my fontconfig fixed the issue as seen in the attachments. If this option doesn't cause any issues with other fonts (it doesn't for me) why not make this the default behavior or atleast provide a preset?