You're using chrome on windows right? The linked URL is their mobile site and the text container has been 3dtransformed forcing grayscale antialiasing which Chrome does poorly.
Check it out on Firefox or IE and you'll see what I mean.
It will look much better on a mobile device as well. If you drop "mobile." from the url you'll get their normal desktop site which also has much better type in Windows Chrome.
I use f.lux, and it's great, but it doesn't affect brightness.
I don't want to turn down the brightness because then I've turned down the maximum brightness. My brightness tolerance runs on a curve - at one end, there's the brightness I'm okay with for the page as a whole; on the other end, there's the brightness that's okay for a single pixel, and they're nowhere near each other.
Logically, then, you should never use #FFF for large areas.
Check it out on Firefox or IE and you'll see what I mean.
It will look much better on a mobile device as well. If you drop "mobile." from the url you'll get their normal desktop site which also has much better type in Windows Chrome.