It's also very fast (apart from compiling ;)) and uses almost 50% less memory than Manjaro on an empty xfce session (160 vs. 300 megs). So gentoo on an old laptop is not that bad idea.
surely in realworld usage terms this means you need 3 equal laptops
one to use
one to recompile for updates
one for spare ready to use incase if a failed recompile issues or failure of in use laptop
and alternate evey 3days ? (or recompile period )
seem to remember Firefox taking quite some time to build from source too
sourced based operating systems apps have their place , like ubuntu does ,just not on my machines lol