Some time ago I installed the Microsoft Clear Type Tuning Tool. This tool allows you to configure your ClearType settings for the best appearing text.
Recently while developing some pages I noticed that some of my larger fonts looked pretty poor. After a little tweaking I noticed an interesting pattern.
No type anti-aliasing:
Standard type anti-aliasing:
ClearType type anti-aliasing:
You will notice that for large-sized fonts the Standard method looks better. However, for small sized fonts (fonts that are 1 pixel wide) the ClearType method looks better.
I can't understand why the "more advanced" ClearType anti-aliasing would produce such poor large fonts.
For web-design it doesn't really matter. I can't control how your computer is configured. I don't even know if you have the same fonts I've choosen. All I can do is try to make my design flexible and to make sure it looks good to the man who pays the bills.
All I can really do is decide which method I want to use. Bummer.