I have no idea what Poser really use, but the Phong and Blinn model are very similar, both use the incident light angle, camera direction and the normal of the point where's the illumination is calculated. The only difference is the mathematics on how these angles are used and in both cases the mathematics are very simple and give in most of the cases the same result. In many cases in 3d engines what is called Phong is really Blinn and what is Blinn is really Phong and beside academical purism it makes no difference the confussion.
The Blinn or Phong models are very simple, give acceptable result, but are NOT physically correct.
There are many models that are physically correct and are mathematically complicated with the consequent big computation time.
The model to be used depend on the object, there do not exist an unvirsall model, the model tio be used depend on the BRDF of the object, research this term (BRDF) for more information.
For example, for metallic surface there is the Torrance model that is physically correct and produce reallistic rendwerings, but the Torrance model only worls for metallic objects. For rough surfaces you have to use other model, for dusty surfaces such as the Moon you need another model and so on.
Human skin requires another different model and is difficult and complicated for producing reallistic results (dielectric, sub surface scattering) and what is worst, human skin has hair!!! and this nobody takes into account....

Stupidity also evolves!