[Plato the Greek]

There is an explanation of the differences in appearance describing a number of different factions or species of Cybermen which evolve or change over time - I read about it in the official magazine many moons past. This kind of stuff is always just expanded universe trying to explain discontinuity though - the physical differences are mainly just the results of conflicting design tastes over time on the part of the writers/designers.

I think the new Cyberman design looks fantastic, especially the face/head. I do think the hands are too weedy though. They should have kept the big David Banks style gauntlets. 17 years since Silver Nemesis...Christ... I can't believe how old that makes me feel.