I used Inventor Fusion to model a pair of glasses (with space inside the frames for batteries and other electronics). This was great for direct modeling with some constructive geometry features. The object tree was also interesting: for example, the ability to combine components through parametric joints. However, I found it to be lacking on hierarchical and parametric 3D features, compared to what I'd briefly seen in SolidWorks. So I spent a lot of time installing Solidworks on my Mac running Windows XP in VirtualBox, but did not get far in actually using it. I also tried FreeCAD and OpenSCAD, neither of which resonated with me.