poser (8, pro) renderer is now alot faster than in old days.  FFRender doesn't officially do indirect specular yet, but when does anybody use that in carrara?  it's very cpu-intensive.  the poser renderer doesn't get much good publicity yet, as most users don't understand shadows nor GI, and they say that poser manual doesn't have enough detail on GI.  but try transparency-mapped poser hair (feature dating back to poser 4, 1999) in either poser or carrara - it will render extremely slowly in either app.