Thanks for comments. And to answer your question RasmusW, no I do use proper topology. I create the ''low'' cage with Zremesher and then create the uv's in UVlayout. I then bring it back to Zbrush and go up a couple of
divisions and bake the displacement map from there. The low cage for this one was around 750k poly's, and then subdivided in Arnold at render time to handle the displacement map. This is my home workflow, at work its a different story.
Here is a couple of screengrabs from within Zbrush.
12 mil for face
12 mil for body