2009
Gentoo Optimizations Benchmarked | Linux Magazine
by greutAlthough 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.