optimized?
 

some distros advertise themselves as being optimized. But, what does that involve? Is it just the kernel that's optimized? If you built it yourself, that wouldn't matter, would it?

I believe it means that the sources are written for specific architecture (i486, i686, ppc etc...) and possibly that the memory management has been streamlined for that hardware? but i could be wrong.

I don't think that it's the sources are written for a specific architecture, but that the sources are compiled for a specific architecture. From looking at some .SlackBuild files in the source directory, you can see that Slackware is optimized for i686 but will also run on i486.

CFLAGS="-O2 -march=i486 -mcpu=i686"

Someone correct me if I'm wrong.