I've finally managed to make a nice toon material without depending on the compositor.
Its driven almost entirely via the specularity ramp, so to add texture you need to use the Material Node, but thats quite easy, and I've included an example in the blend file with a cartoon tone material (all those small dots you see in comics) the material could be improved, at the moment its just a modified brick pattern inverted and rotated to create a diamond pattern of small dots
that's amazing!