Just removing the font-weight: 300 helps tremendously. Personally, I'm becoming less of a fan of external fonts. I've noticed lately that they're often the slowest thing to load on sites that use them (especially Google fonts).
Original: working on a standard DPI Mac, but it still looks fine - see http://imgur.com/WRWYzBx. Trying to figure it out now...
Cause that looks like a printer that ran out of ink.
It's painfully thin, and the eyestrain factor is pretty high.
But you don’t notice it until you open a font selection menu.
But seriously, I had to use Gtk3's font selection menu today, and it was impossible to work with it.