Soft shadows....drives render time up REAL fast. Photon count likewise (I had to roll my "First Quest" pic up to 8,000 photons to get smooth coverage on the walls). Transmapped materials when there is light interactions (that is, radiosity effects). But this was my experience; with comparable settings, faster than Poser4. With GI switched on, faster on a comparable scene then Bryce4 with a thirty-light skydome.