I use other applications for toon rendering usualy…
I do archetects modeling for presentations,
and sometimes I do real time simulations for blood sucking lawyers.
I do all my modeling in blender now… I am also starting to use the toon shader and ramp shader a bit more…
the outlines and solid colors are nice for some illustrations, and visualizations.
right now I am useing Truespace 6.6 and some toon shaders i have found on the web … and also some I have purchased from simbot , and Calagari.
in the near future (next project perhaps) I am going to be useing blender and Crystalspace, rather than Truespace and 3d game studio…
in the past I have made and used Toon shaders in Zbrush… Zbrush is too hard to get things exact, and with the correct perspective, so I dont use it too much for rendering.