I equate Gentoo to Ubuntu/Fedora/OpenSuSE.
That's a little harsh... Gentoo does abstract compilation / linking / installation
by default. When a package is missing from the Portage tree, or the latest version is outdated, you can simply create an ebuild yourself. And to do it properly, it's best to first build, link, install it "by hand", the dirty way, and then make an ebuild out of what you just learned the hard way (while keeping flexibility with USE flags), for a clean installs.
Using Gentoo just means your package installs take longer, not that you understand more of what's going on.
Always installing from the source code doesn't
only mean longer installs (not so long with SSDs and today's fast processors anyway, that applies to even the kernel), you're also compiling with only the features you like ("configure" flags, abstracted as USE flags) and optimisation levels of your choice... with dependency resolution and sandboxed install taken care of.
If compilation time really is an issue, packages come in pre-compiled binary form as well (maybe not for all architectures though). It's just an option to "emerge" to specify.
It is not a "down and dirty" distribution.
Again, it's not
by default since its package manager is the recommended way to go, but it can very well be "down and dirty" if you want, there's nothing that prevents you from doing it all by yourself. But then, you're on your own with messy installs of course.
Gentoo is like a superset of pure "down and dirty" distros. It gives you a clean slate to start with. You can either stick with the clean ways, or deviate and handle the cruft leftover from manual "make install"s.