Yeah, you know, Vue's booleans, for example, are similar to Bryce's---not truly boolean objects, per se', but they stil work-- in the program, at least. Otherwise, I'd recommend Rhino, for all modeling needs. I've never tried RDS, because it was "orphaned" before I came on the scene, and I haven't tried Carrarra, well, just because it also seems not only out-dated, but orphaned as well........ But I would highly recommend Rhino-- expensive, yes, but nearly flawless, and not likely to go anywhere any time soon.