I realize how bizarre this must sound, but my first reaction upon visiting that page was that the font was just too large to read comfortably. It only takes a quick ^- ^- to remedy, but it's an amusing counterpoint to all the recent frustrations with sites that insist on using 10pt fonts.
Yeah, I've noticed this on a couple of sites too, particularly the default Octopress theme which (like this site) sets the text size on the body to a bit over 1em, and I don't understand why anyone would do this; what platforms are they developing for, where the default font size is too small? Obviously, better to have the fonts too large than too small, though.
No, I'm used to 1em being a reasonable size for body text - the text at that link says as much, but for some reason sets its own body text to 1.3 times browser default. I don't particularly object to it, I'm just curious as to why they think the browser default is too small.