I have been using Archicad supplied by Axonware for 15 years. Archicad is an intuitive and powerful application for architects, transitioning from 2D cad to Archicad has saved a significant amount of drawing time, particularly when making changes to drawings. The ability to send clients the 3D model in BIMx format for them to explore on the free viewer app has lead to clients enthusiastically buying in to the designs at an early stage.