I generally simply avoid them and use better fonts (e.g. the Lucidux
font family, the MS Core ones without "Comic Sans"). There are also
fonts that FreeType's Postscript hinter doesn't render too well too,
but this will be improved as time passes.
Improvements tend to be slow and difficult because any algorithmic
change routinely break the rendering of certain fonts while improving
others.. :o(
Note: I'm using 2.0.6 exclusively on my laptop and home machines,
_without_ the TrueType bytecode interpreter and the result
is very pleasant as long as you avoid the ugly fonts..