The older Canon flashes, with a "Mark II" designation, were released to give just that, full menu control support. Later units, like the 270 and 320, have this from the beginning, so no need for any "Mark II" there.
You should also realize that if the 580 EX is a class 2 flash and the 580 EX II a class 1, then the 600 EX-RT must be a class 0, since it not only implements and supports everything you can set from the menu of the 1D Mark III/40D (first cameras with flash menu setting support), but the 600 EX-RT also supports settings only the 1DX/5D Mark III and later cameras can access.