In my day job, I am a senior research software engineer at Newcastle University in the UK. I use my 3D printer to print stuff for outreach activities, gifts and just for fun.

I refuse to use any commercial design software, firstly because I prefer to support open source and secondly, because none of it runs on Linux. In this day and age, if a company charging money for their software can't port it properly (i.e. without emulators) they shouldn't be in the business of software development.

So, I mostly use OpenSCAD because I have not yet had time to get my head around Blender or FreeCAD.