Most outline fonts are often drawn blurry or weak on Windows if they don't have any bitmaps. It's quite sure that ClearType technology has improved its rendering quality and alphabets get definetely clearer than Mac OS X, however, some complicated glyphs such as Japanese kanjis look somewhat distorted by contrast. The new japanese font Meiryo, shipped with Windows Vista, seems much better and still clear even in smaller point sizes, but this is not a fundamental solution at all, because the other outline fonts still look quite poor only on Windows. It can be said that the font is one of the most important and hottest elements on GUI design. As a Windows user, I'm really annoyed at the fact that the rival OS has better font rasterizer than that of Windows which has the largest market share in the world.