The problem with using an external renderer like Bryce, DAZ Studio or Vue is that you
lose all your Poser shader nodes.  Clouds, noise, blender, color math, those sorts of things.
Though Vue 6 is supposed to be able to incorporate the Poser shader nodes. 
About all that transfers over now is the root material node and image maps.
Also you lose your lights and their settings so you have to set up your lights all over agin.
Does POV-Ray import in the Poser shader nodes and the Poser lights?
Myself I think Firefly is a damn good renderer if it is set up correctly.
In the time it takes to learn another system you could instead be learning how
to use Poser correctly.
Just my opinion.