Gentoo GNU/Linux

I suspect there are more serious GNU/Linux users here than on /g/ so:

What’s the advantage of using Gentoo, or having a similar system with a package manager that compiles the software from the source, compared to using a distro like Ubuntu that pretty much just uses binaries?

Thanks.

Compiling for your specific hardware will make some things like the kernel perform better. For the most part you won't notice unless you're running on ancient hardware. I prefer FreeBSD that has both source (ports) and binary (packages) managers.

Archlinux has the option of downloading sources and binaries as well.

Compiling every peace of software has other advantages than the shallow "kernel perform better" every software package performs better plus it compiling with your own preferences takes off a lot of dependences that other distributions just force to you! You can still have those dependences if you need them but again "It's your choice" that's what Gentoo is all about giving you the freedom to customize your installation true the easiest way possible (by that I mean Portage and the unique flag system).