"The one that is useful and which no other program can replace for you is the Multi-Pass rendering."

Actually ren_mem Poser has had Render passes for a long time now.  It's under "Scripts".  I only have Poser Pro on this computer, but it even allows you to select how you want your shadows handled (ie separtate passes).

I've used it for a few things, it is a handy little feature.