11.

There wasn't really anything added to 12, other than the Principled node and a small tweak to the comic preview options, that piqued my interest. Also quite a few scripts I use don't seem to have comparable substitutes.

I went from 8 to 11 after being away from the Poser world for a few years, using Carrara mostly. I switched to windows when my old mac died and bought 11 cheaply. Both version 8 and 11 seemed like watershed releases, 8 with IDL and the dependency editor, 11 with Superfly and a host of content creation automations. I'll be purchasing 13... just because... not because there seems to be anything comparable to the steps forward that 8 and 11 made. I was looking forward to full unimesh and what avenues that might open up, or at least a new toy to play with.