From an aspiring architect’s perspective, the only apps that make sense to use at the moment are ArchiCAD or VectorWorks. ArchiCAD is arguably more advanced than VectorWorks in that it’s fundamentally all 3D at heart, whereas VectorWorks isn’t. That said, there is plenty of 3D design capability in VectorWorks, it’s just that it still segregates between different views and can actually be used as a 2D app. You may consider that old-fashioned and not cutting-edge enough, on the other hand, VW has less of a learning curve. Is it proper BIM like ArchiCAD? Opinions differ. I’m on the fence, personally: I’m more familiar/comfortable with VectorWorks, but I do like the ArchiCAD philosophy.
As for the ‘popularity’ of AutoCAD, I think that’s potentially misleading. Certainly, the application is pervasive throughout various sectors of the building industry, but using that as an argument is similar to advocating using Windows over OS X because it’s more ‘popular’. It doesn’t make sense. From the modeller’s perspective, the ArchiCAD-OS X combination is a superior choice to AutoCAD on Windows, which is an arcane, poorly designed app on an inferior platform.
The way I see it, the only thing that ultimately matters is the relationship between architect and client. If elements of the building industry are overly conservative and demand 100 per cent AutoCAD ‘compatibility’ (identity), that should not influence the software choices of the person who is actually designing the whole damned thing. Rather, he should use the finest tools available to produce the best product for his client. Anyone arguing that AutoCAD is somehow a better or even equivalent modelling tool compared to either ArchiCAD or VectorWorks is probably not a visual thinker.