The recent Freecad 0.18 adds in an excellent 3 axis movement tool for onscreen manipulation of parts or objects in your model. This feature alone has saved me 90% of the time I used to waste on visually and accurately aligning and adjusting the position of objects relative to one another as opposed to straight parametric value entry.
I have been using FreeCad since 0.15 and it has evolved into a very fast stable platform capable of anything I need done within our complex mechanical model. Having worked with Autodesk and Solidworks in the past its a b reath of fresh air.
Also the macro function works extremely well for creating animations and the built in Python console and interpretive language is useful for more complex animations or automation of part builds through a form.
The export function to other formats requires a 3rd party add on for Solidworks, which lags behind the latest Solidworks formats, which can be a problem if you are working with contractors or also a contractor supplying work into a Solidworks environment, as you will likely end up sending export files in a recent but not exactly current Solidworks format.
If you are working in the mechanical engineering design space as a contractor or business, look no further. FreeCAD is ready for prime time mechanical design as of FreeCad 0.17.
FreeCad solved the biggest problem for most in my case which is budget for Big CAD software, I did not have one. FreeCad was able to import my airfoil .dat files flawlessly and scale them to the correct size with the clone function in the Draw pallete, which is extremely useful for rapidly scaling up a model, as are the mirror tool in the Parts palette. Also FreeCad makes it easy to build with basic 3D shape geometry and rapidly create wires, faces from object edges or vertices used by the Parts palette extrusion and lofting tools.