Another reason why human Poser figures tend to look unrealistic is because invariably they have totally symmetrical faces - real humans don't.

Look in a mirror, there are subtle differences between one side of your face and the other.  Most are almost too small to recognise, but the subconcious sees them as part of the recognition process.  When they are missing it says "something wrong here".

Try making very subtle adjustments to the face in Poser; size of eye, degree of closure, size of cheek, one side of mouth smiling less than other, height of ears. The list goes on & on ... ... ...

Try it - I think that you will be pleased with the results.