It's funny because I find OSX's font rendering to be a blurry illegible mess, and would hold cleartype up against it for on-screen legibility any day.
But that all hinges on what you're used to looking at more than anything else. Just be glad it's not fre e typ e wi th it s re tar ded ker ni ng of tex t.
Both freetype and the apple renderer claim to be closer to print in appearance - I don't find blurry and illegible where two instances of the same word don't even render the same on screen to be consistent with print. YMMV.
It also may simply depend on what fonts you're declaring... OSX and Windows typically have different base fonts, and if the font you are declaring doesn't exist on the windows machine, you're **** out of luck.
Expecting ANY form of consistent font appearance, even using webfonts, across platforms is unrealistic at the best of times, nonsensical at the worst.
It's really a tired old argument that comes up time and time again. Basically Apple's renderer is more concerned about preserving glyph shape than with legibility -- Windows is more concerned about legibility by hammering lines into pixel boundaries, to hell with "glyph shape". It's hard to say who's actually "right", I just know I personally prefer Window's improved legibility.