Thanks, Tim. The history tree concept sounds a little bit like the way Pro-E works, in a way, with object-oriented lists. So, basically, as in ArchiCAD, if I move a wall, everything that was attached to the wall will update along with whatever changes I've made.
What level of detail is possible? I know this is driven by my computer's RAM and processor speed, as well free disk space; for example, in SketchUp, you wouldn't want to make your walls contain all the physical layers of materials (sheathing, gyp board, studs, etc.) that the actual structure would have (unless you're doing a 3D detail), otherwise, your model becomes very slow to work with. I imagine the same applies to ViaCAD?
Granted that SketchUp's pretty limited and it's geometry rather simple, but, if ViaCAD can export to Catia, I imagine the modeling can get rather complex, as Catia is used by automotive stylists, who have to deal with compound curves, etc. This requires a level of 3D tools that is beyond most modelers on the market. Since ViaCAD is intended to be used by designers in every industry, I can understand how there is a possible balancing act to perform in terms of user-friendliness. You don't want your tools to be so complex that some market segments won't use them, but, on the other hand, you don't want to "dumb down" the tools for designers who are accustomed to a certain level of complexity, either. So, I imagine ViaCAD is somewhere beyond SketchUp, but how does it compare with, say, 3DS Max, again, in terms of user-friendliness? Bear in mind that I've tried many modelers and SketchUp is the best suited to my skill level, so I'm reluctant to buy something that I may not be able to use use effectively, or that I'll have to spend months learning. My primary interest is in architecture, not high-tolerance machinery or automotive styling, so I don't require a very sophisticated tool palette.
Gary