Why not Vicky4, if she is nice and better than Vicky3, why not?
I liked Posette, when Vicky1 or 2 were released I almost never used her because I found her uggly.
When Stephanie was released I liked and so, replaced Posette by Stephanie.
When Vicky3 was released I loved her and turned off Stephanie.
If I like Vicky4 I shall use her, more polygons is not a problem, what makes the render slow is the Operating System and huge textures and transparencies.
You don't need huge textures unless you do first plane face renderings, resizing to 2000 or 2500 pixels is just enough.
You don't need 100M of morphs only just few Megas of the morphs that you use and about the Operational System I am not guilty if you use Windows Vista!

Stupidity also evolves!