So here is a test-render of a boxer, based on my previous boxer model. I just altered the head and anatomy a bit. It was rendered in cycles, and though this render-engine doesn’t support normal maps yet, the result looks quite decent in my opinion. The skin has been painted and generated with Zbrush.
I did not have much success using the Zbrush maps in Blender and the blender internal render-engine in the past. The Displacement Maps f.ex did not show a smooth result at all. However, this seems to have changed with Cycles. Those two programs work together very well in my opinion.