I may give houdini a try. I've only ever tried rigging in blender and zbrush. Blender is my package of choice for hard surface modelling, but the rigging workflow is just.. onerous. Zspheres are way easier, but I don't like the hard surface topology most of the time. Zspheres are also missing a lot of the advanced rigging features blender has. Usability has its tradeoffs I guess.

Thanks for the chat Rayalez! :)