it may be a typo - true IDL (not available in poser8/pp2010) vs. true IBL (may involve bad sphere mapping and fake fx like AO).

realism as a popular artistic style comes and goes over the centuries, but one criterion of a fully-fledged render engine is its ability to do a scene with no obvious rendering errors IMVHO.  hence one might compare the blown-out nostril-glo poser 4 things in gallery and marketplace promo images with something by somebody who knows how to use FFRender et al.