EZSkin works by replacing the shaders that came with the character skin texture with a set created to exploit the advantages of the newer rendering options in Poser 9 and Poser Pro 2012 (specifically, subsurface scattering). It does not matter what the original shader was like. It will be completely over-written by new ones based on what you plan to do, and how you want the skin to render.
Version two has been completely rewritten based on user feedback and advances in techniques discovered by Bagginsbill to give you simple, powerful control over most of the details of the skin shader. It has the controls organized on multiple tabs to make it simpler to find the parameters you want to adjust. It also incorporates the ability to add characters to the figure recognition list without having to edit any XML files, as was the case in version one.