Which forum over at RDNA?  The Reality for Poser forum?  If it was stated there, take it with a grain of salt.

Unless you truly need an unbiased render and have the days and days to tie up a system just for a single render, learn to use Firefly.  No, it's not the be all end all of render engines but Poser and Poser's materials, shaders, lights, ect are all optimised or use in Firefly.  If you are using Poser created content, Poser's render engine is where you are likely to get some of the best results. 

I know there are those who don't agree.  In the end, what render engine depends on many factors that are unique to each user.  You pretty much have to figure out what you need or want from a render engine.  There is no right or wrong, good or bad choice.