Thanks for precisions

@Frank_g :
For warez copies, people can not sell a product made with illegal version.
Im' not sure it is a problem for Pixologic of illegal versions :
the main Zbrush target is lot more game , video and other media industry than hobbists.
And in industry, they use legal software.

I own 3D Coat that is very good, but re tested once again from years Zbrush yesterday, and yes, it is really powerfull and very smooth and fast.
You can sculpt big volumes without performance issue (3D Coat uses Voxels that allow lot more things but asks lot mroe processing power) !
I perhaps gonna buy it these days (lot of money ) !