Tailwind seems to be more mature and better documented. Apart from that, they're pretty similar, so if you're used to one you probably won't get much of a benef

Tailwind seems to be more mature and better documented. Apart from that, they're pretty similar, so if you're used to one you probably won't get much of a benefit from switching to the other. I see that the example websites from Tailwind look much better than those from Tachyons, though I'm not sure whether that's just a matter of taste.