Be careful with this! It's a slippery slope from LFS to Gentoo. I made the mistake of trying LFS once in college, and then I spent the next 10 years compiling everything from source! Beware!!
Gentoo has its problems, but I can't imagine life without it. The day I can't use Gentoo is the day I quit tech.
The people who I know that use Gentoo are addicted to constant updates (they apply them more than once a day).
There is something about compiling non-trivial software, like the kernel, with all that text flashing by the screen, that is purely satisfying to watch.
Quite the opposite for me. I struggle to do it once a month. I would often go months without it, but that turned out to be a really bad idea.
No - it's the USE flags that make it awesome. And the ability to apply custom patches, etc as needed.