I used softimage for modeling parts of a fence that I would later use in Houdini to create a customizable fence that could be modified for an environment on the fly. I also used Softimage XSI to model a vehicle. I chose to model a Jeep Wrangler.
I found that Houdini can be much more useful for procedural modeling purposes and simulation. I created a variety of models that were pretty easy to finish quickly in houdini, but would have taken a long time to do in Maya.
The simulation projects that I did were some dominoes, a marble machine, and I used my vehicle model and crashed it through a wall. I also created a customizable earthquake crack tool that can be animated.