If you are using only distro-supplied fonts, the new fontconfig makes them look better (but at the expense of most imported TTF fonts).
Also, if you are a kde user, the new fontconfig will break some of the font locations for fonts you've added with the kcontrol font installer (such as the terminal font that allows the "linux" font to work for console.
Here's my local.conf from a slackware install. Copying this to arch fixed everything back to normal for me (TTF's installed, KDE user):
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
<dir>/usr/local/share/fonts</dir>
<dir>/usr/X11R6/lib/X11/fonts</dir>
<dir>/usr/share/fonts</dir>
</fontconfig>
You really don't need the anti-aliasing info in local.conf - just the font directories.
]]>Any ideas how to improve it?
]]>NoUpgrade = etc/fonts/fonts.conf etc/fonts/local.conf
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<!-- /etc/fonts/local.conf file for local customizations -->
<fontconfig>
<--
Disable anti-aliasing for fonts that are size <=12
<match target="pattern">
<test qual="any" name="size" compare="less_eq">
<int>12</int>
</test>
<edit name="antialias" mode="assign"><bool>false</bool></edit>
</match>
-->
<--
Enable sub-pixel rendering
<match target="font">
<test qual="all" name="rgba">
<const>unknown</const>
</test>
<edit name="rgba" mode="assign"><const>rgb</const></edit>
</match>
-->
<--
<match target="pattern">
<edit name="dpi" mode="assign"><double>100</double></edit>
</match>
-->
</fontconfig>