I think the draw of pacman is that it's really simple. (Actually that's the draw of Archlinux overall.) Pacman is fast, useful, and you can learn its feature set in ten minutes. Apt-Get is considerably more complex by comparison. Especially, and I think this is where pacman really shines, is making new packages. All it takes to build a pacman package is simple PKGBUILD file. This is analogous to a Gentoo ebuild but much simpler.