@Bill
Gladly.
OpenSCAD
Very easy to use for those with programming experience (or who think like programmers). Very suitable for its intended purpose; creating meshes for 3D printing. Unfortunately, the very few file types it exports are not well suited to the 3D CAM package that we use at the Makerspace, FeatureCAM.
FreeCAD
The first 3D design I produced for the HAAS was done with FreeCAD. The software is still in the early development stages, version 0.15 as of today. It is able to write (and read) two types of 3D CAD interchange files; IGES and STEP. Our version of FeatureCAM can read IGES, but not STEP. I was able to open either type with AutoDesk Inventor.
That first design was fairly simple; a fixture plate with about 75 holes (for clamping parts). The IGES file produced had some issues; most notable the actual cube for the fixture plate was not imported by FeatureCAM, just the holes. I was able to use it, but only because the block of material wasn’t being changed in anyway.
On a second attempt with FreeCAD, I modified a design file that was part of the SatNOGS satellite tracking station to accomodate a US pipe size versus its original metric size. Simple change, but the STL mesh file produced by the change was no longer printable (A torus appears in the stl about two inches above the part).
Feel free to ask me any other questions you might have.