C6Pro is still better and faster than FFRender.  it has caustics, transparency colour, easier to use
hdri, and reasonably simple controls of what they call "GI", one part of which is indirect diffuse
illumination (IDL in poser).  also has GC in render settings.  i was griping that the free trial of
C7Pro wouldn't work in snow leopard, but then I found out it was an upgrade, not full version.
was able to run and install C6Pro in snow leopard after editing prefs file.