Real Skin Shader is a relic of the past, no longer a usable product with the current Poser versions. 

Actually, I use both the old V4 Shader and the RealShader updated for P2012 with no problem at all. I use them for quick renders. The only issue might be some artificial AO that's not necessary, so I manually adjust it. They are both updated to work with Poser's latest Python calls, IIRC. I am terribad with EZSKIN. :) I can only rarely get it to work to yield a render that's only slightly better than skin that looks like bakelight... But, I don't render much and, when I do, it's just so I can see whatever it is that I just modeled and how it looks. I should probably work more with it, just to see how amazing it is.