Although we are not comparing apples to apples, Gentoo did out-perform Ubuntu in almost every test, and sometimes by a fair margin. It does appear that optimizing for a specific CPU can yield a decent performance increase.
Of course, Gentoo offers benefits in other areas with their USE flags and being able to build a highly customized system. The question is whether the amount of time it takes is worth the benefit, and that’s a personal choice.
A quick survey shows that seven of the Alexa U.S. top ten web sites have a SCRIPT tag above their stylesheets or STYLE blocks: AOL, Facebook, Google, Bing, MSN, MySpace, and Yahoo!. These web sites don’t currently use @font-face, but if they did, they would experience the IE blocked rendering problem. This raises the concern that other web sites that are early adopters of @font-face have a SCRIPT tag above @font-face and their IE users run the risk of experiencing blocked rendering.