Many posts here talking about retraining time and familiarity. I have used SW for five years and PTC CREO/Wildfire/Pro-E for more than twenty. The simple fact is that while FreeCAD is a nice try and has some useful features for very simple work, it is not even in the same discussion group as "real" CAD software. A similar thing can be said regarding program for FEA and CFD analysis. The irony is that Pro-E was actually developed for Unix (OK, Solaris) and abandoned that field. A sign of hope is some of the newer programs, like Abacus, will run in a linux environment. But there is no indication that any of the full-feature CAD and analysis combination packages are even remotely thinking about running in linux. I manage better than most commenting here with LibreOffice replacing Word and exchanging documents with my Microsoft-laden friends. But there is a Win7 workstation under the desk to run SW and CREO that I would love to replace but cannot.