Archicad is superior in my opinion. I am using AC since the V6. It has a bigger learning curve for sure, but the power is customization. I agree that CA is more streamlined and "efficient" in some cases, but if you customize Archicad with the profiles for your needs it is just as efficient. You have to invest time to create different profiles for different projects. Someone mentioned in the thread that Archicad is owned by the same company as VectorWorks. That is true, but the workflow of AC was established way before the acquisition by Nemetschek . I personally was afraid that they will change things for the worse, but luckily it did not happen. I am not a fan of Vectorworks at all. I use Chief only because they have good residential libraries available, and some customers use it.
One more thing; you don't have to use BIM or even think about it to utilize AC. I know I sound biased, but believe me once you get used to AC there is no need to use VectorWorks or AutoCad.