It's been my experience that Ubuntu's default font rendering is good--but this seems to be because Ubuntu is using fonts which have been explicitly designed to

It's been my experience that Ubuntu's default font rendering is good--but this seems to be because Ubuntu is using fonts which have been explicitly designed to render well in the Linux font stack. I find that using mainstream TTF and OTF fonts, with their custom hinting and ligatures, works less well. Soon this will be a non-issue, though. Font engines differ only in how they hint and subpixel render at low resolutions. Once every display is "retina," there will be very little difference, except perhaps in gamma correction, advanced kerning and layout algorithms, where I've found OS X has always produced superior results.