Deelip Menezes this last week wrote a series of articles that ended up becoming a thesis on the future of CAD software for mechanical design. I'm not sure that he intended it this way, since you can detect the development of thought, going from one posting to the next.
- "Real" MCAD was parametric-based since PTC burst onto the scene.
- Direct modeling was the underdog technology employed by CoCreate, IronCAD, Cadkey (KeyCreator), and others.
- Direct modeling was not taken seriously until SpaceClaim arrived. (Coincidence? Perhaps.)
- Since the arrival of SpaceClaim, direct modeling was added to Solid Edge, NX, and is being added to Inventor and Pro/E, with something vague happening over in France with Dassault's software.
- That leaves SolidWorks and Alibre with no direct modeling roadmap.
Mr Menezes' summary: customers are being (will be) dragged into direct modeling by CAD vendors, much like the ribbon interface being forced upon them.
I recommend you read his series, the many comments, and muse upon them:
- Inventor Fusion and SolidWorks Confusion
- AutoCAD Fusion
- Kernel Confusion and Legacy Models
- GRANITE Cross-Release Interoperability
- What is Digital Prototyping - Part 2
- Kernel Conclusion
- Direct Editing and the Future