Arch is not basically gentoo. Gentoo is about as close as you can get to vanilla Linux while still being a distro. Arch is pretty opinionated about what defaults should run, gentoo is explicitly flexible. Also the compiling on gentoo thing really needs to stop, there have been binary kernel packages for ages, even before the recent improvement to binary packages. The gentoo installation in someways is easier than the arch installation, as long as you use defaults and customize after first booting up, and if you really want to customize stuff, portage is an absolute beast.