When I was deciding whether or not to buy I took identical sized texture templates (head and body) for V3 and SP out of UV Mapper, put one over the other in Photoshop and clicked the top layer on/off - a poor man's blink comparator. There was infinitessimal movement on the nipples, and moderate movement around the outer ends of the eyebrows: if I can't do that with the liquify filter in PS I'll buy the plugin, but for now I've passed.