A mate of mine back home ran CGX on PicassoIV. Not sure if he still does but I'll ask him some point this weekend.
Personally I use CGX because having a BVision I don't have much choice :-)
On a related note, I've been looking for permedia 2 hardware info all week and found a fair bit of linux source for frame buffers etc. Does anybody know if this material would help write a Picasso96 driver for BVision/CVision? I ask since I'm doing quite a lot of gfx programming just now and haven't touched P96 (since I can't test it)...