it is source-based. in my experience this means mainly three things:
- if something breaks or doesn't compile I can fix it myself without having to search internet forums and such
- I can set compilation flags to adapt programs to my needs and environment
- it is easier to create and maintain my own packages for the package manager
I use it mostly for Recreational Programming, I often browse github for libraries for my projects and most of the time they aren't popular enough to be in the package repository of any distro. with gentoo I can write an ebuild and have the library installed and maintained by the package manager in less than 5 minutes
it fits my use-case well but I don't know if I would recommend it to other people. it isn't hard but you need some experience with c/c++ toolchains, autotools and cmake for it to be anything more than just another distro with less support than debian
now that I think about it, one notable thing is that gentoo doesn't do stuff behind your back so to speak, so there aren't as many opportunities for things to break unexpectedly. I guess that can be a plus even for inexperienced users
