Depends. Some Poser renders are just awesome out of the box. Why mess with perfection. Sometimes I do compositing (Have to the way I do my comic book covers.) Heck, adding your signature to the image is postwork. Sometimes you want a certain effect or look that Poser cannot do out of the box. So why not. So it depends. I wonder if postwork is to a Poser user as Poser use is to a "We build our own meshes using THESE apps" user?

"Few are agreeable in conversation, because each thinks more of what he intends to say than that of what others are saying, and listens no more when he himself has a chance to speak." - Francois de la Rochefoucauld

Intel Core i7 920, 24GB RAM, GeForce GTX 1050 4GB video, 6TB HDD space
Poser 12: Inches (Poser(PC) user since 1 and the floppies/manual to prove it!)