Hm. I know this thread is a couple years removed from the last post, but considering Zbrush has only recently released a new version (2019) and Sculptris is now fully integrated into Zbrush, it might be a good time to talk about a little history regarding Sculptris... Sculptris was originally created by Tomas Pettersson as an "alternative" to Zbrush style sculpting. It was one of the first sculpting packages which did not require you to subdivide the mesh into millions of polygons to get the detail you needed. It has a brilliant method of adding detail as you sculpt, which was previously thought to be impossible with the technology of the day. However, with some very clever mathematical algorithms and programming, Tomas created what was to become a technological breakthrough in digital asset creation. Pixologic (Zbrush) noticed the brilliance and simplicity to this style of sculpting and immediately scooped Tomas up to work for them under the Pixologic umbrella. At that time, the software known as Sculptris was still only in Alpha stage, not even a Beta yet. Pixologic didn't want the Sculptris software as much as they wanted the technology behind it. So they offered Sculptris as a free download to get people interested in sculpting, and have since integrated the tech into their flagship Zbrush, along with enhancements and improvements to the feature sets which were part of Sculptris. Sculptris PRO is now a fully fleshed out feature within Zbrush, and combined seamlessly with all the existing brushes, alphas and features of Zbrush itself.