As promised before, I've decided to go ahead and write about Gentoo. Like Arch, Gentoo is also one of the most customizable distributions of Linux, though it takes a bit more time to install than Arch due to having to compile literally everything.
Gentoo has it's own build utility though, that the name of slips my mind, it's easily accessed using the command emerge. Installing Gentoo is done completely through said command.
Like Arch, It can be proven difficult for new users to install if they don't know how to partition the hard drive or how to use basic shell commands, it's best to read the installation guide if that's the case.
Also like Arch, the most basic installation is a Kernel, Shell, and a copy of the GNU Compiler Collection. Installing other software is as simple as typing emerge then the name of the program unless the program is somehow not included in the source code repositories, using emerge automatically takes the system through the build steps to compile said program making the task much simpler.
My honest opinion on the score I shall give Gentoo, 7.9/10, due to the slow install process. I'd prefer Arch over Gentoo for that reason alone. Gentoo is mainly for people that like to have the binaries completely tailored to the hardware their PC has.