Not for the purpose of an exact likeness, more for the expressiveness - and it doesnt get more expressive than an animatronic head of arnold schwarzenegger depressurising in the martian atmosphere
And this is a test of the very capable, and very FREE Sculptris
Its not ever going to replace Zbrush, but its very simple, streamlined and fun. Pretty much an ideal introduction to 3d-sculpting. For nowt.