I haven't tried Bastard bios myself, even though I'm a Bastard dealer. I hear they're a big improvement over any other bio-BB out there.
But I'm leary of bio BBs in general. Any time I've used them, they've caused jams, have filled by barrel with gunk or they've broken in the mag or feed path. It's left me very reluctant to try any brand really, even Bastards.
And I second what venture said. They don't mind the greasy mess left everywhere behind by paintball spooge, but mind inert plastic BBs? That makes sense.