Which optimizations should be done for Ubuntu, as you, after all, can compile your own package for Ubuntu (and Debian) too, using about the same optimizations as for Gentoo.
You don't understand, the point is to make Gentoo win the benchmark, not vice versa! I mean, otherwise the benchmarks will just show how pointless it is to turn to Gentoo purely for performance reasons.
I wonder why they didn't test 64bit though. Who in his right mind would use Gentoo on a 32bit (i.e. Atom) CPU anyway?