ello,
what's your pipeline for getting stuff out of ZBrush into 3DGSD ? Just saving as OBJ and using MED to import ? How are you handling the UV-map ? ZBrush's "tiles" are great IN ZBRUSH, but pretty hard to use outside of it.
Have you tried some hi-poly stuff with ZBrush 3.1 yet ? I played with one of their sample objects, pushed it to around 4 million polys and then went crazy and used the HD-divide to up that to around 30 million polys

As you said ... it is just plain fun !
Did you work with any normal map and/or displacement map stuff out of ZBrush yet ?
Cheers,
Andreas