Isn't crunchbang a debian distro with openbox? You can put openbox on any distro you like including arch if that's what you are after.
That's kinda what I expected, an out of the box OpenBox setup built on top of Debian. It does say they use packages from their repository so there must be some differences than if you did it yourself.
As great as Arch's documentation is (best in all linuces I've tried), I still prefer to have some nice defaults so I can get stuff done whilst learning the knobs.