You can really see the difference in the base where there is that large, relatively flat area of glass. The default settings leave is very noisy and without any subtle details, whereas the transluscent one has this nice, deep, 3D glow to it. Of course the 30x increase in rendertimes mean it's not going to be useful for 95% of scenes... Here's a Bryce 5 (five) render using the same render settings but my own lighting scheme and an image sphere, which is a low-dynamic range "cheat" to give the look of HDRI. You can see the transluscence in the glass block. This scene, however, took 42 hours to render.