Infin-D must have been a pretty interesting program for its time given that people are still talking about it ... I gather if one tried to use it today, though, the render times would seem very slow. To me where C's material system (which does allow you to do some pretty nice procedurals using the mixer concept) gets confusing is when you want/need to have multiple textures on different parts of a single object. C4D handles this through selection sets (you select and name a bunch of polys and then you can apply textures just to that named selection) and Lightwave lets you define different surfaces to go with different polygon selections (and then those surfaces can be textured separately). Unless I'm missing something, C's way is much more cumbersome (detach, cut and paste in the modeler and then fiddly layer lists when texturing).