I use Solidworks a lot for designing 3d printed parts for hobby projects. For me, the biggest thing missing from open source alternatives is assemblies. Being

I use Solidworks a lot for designing 3d printed parts for hobby projects. For me, the biggest thing missing from open source alternatives is assemblies. Being able to do constraint-based assembly of your parts and see how they fit together makes a massive difference when designing more complicated structures or mechanisms, but even for simple things like designing an enclosure for a PCB. I’m aware that FreeCAD has some prototype assembly plugins but they look very experimental.