Yes, you can put both (as i do). And make 2 different boot partitions: one for mediator/voodoo3, and one for bvision.
What about planetpotion and other ppc/warp3d demos from 'potion' , you need a bvision/cvision only. Becouse in this demo, hardcoded values for 15bit screens i think (which supported by bvision only). Also, i can said that warp3d driver for bvision and for voodoo3, have tons of differens, and for example if prod will works ok on bvision, on voodoo3 you will have sometimes problems with poligons and colours.
So, for me best way have both (voodoo3/bvision) at the same time. It works fine.
btw, here is ppc demos realted site, mostly is warp3d. You can browse the 'requirements' in download sections, and see, where it was tested and how it works.
http://ppcdemodb.acggbg.org/
