As good as fygomatic's likenesses are, he still uses a limited set of angles and expressions.

Poser heads are hollow shells and not skulls with muscles and skin over them. The best likeness ever created will slowly become unrecognizable as expressive dials are changed because those dials will be adding an expression for the original underlying figure (V4, V3, etc.). To truly capture a likeness, a person would have to create expression dials specifically for that likeness to retain the resemblance beyond the initial emotionless morph.

My visual indexes of Poser content are at http://www.sharecg.com/pf/rgagnon