Sales also increase when developers finally create the drawing RGB on the texture map with realtime navigation and symmetry(as in Mudbox or at least as in Mari) ;). ZBrush would be a package not only for sculpting, but for texturing too, for example, to draw microdeal bump map(skin pores) above the level of geometry detail is not yet possible. Can’t do that the developers or don’t want I don’t know, I think that most likely they don’t want (not high priority).
PS: My computer is not powerful, the opposite is rather weak, but with details in 4096 it work without problems