The general description does a very good job at showing off the true value of ArchLinux. I can only add that I've tried most of the current distros and right now I'm a happy Arch Linux user. The other distro that managed to catch my eye for a generally long period of time was Gentoo, because of its high custumization level. However, the package manager in Arch deals with binary packages, hence you don't get to compile software for hours in order to install it. Being the non-Linux expert that I am, for me Arch is almost a Gentoo with quicker installation and update.
Not for newbies, however. At least not for those afraid to read and intimidated by configuration files...