I've used it a little for openscad with mixed results - sometimes it worked. But I'm a beginner at openscad and suspect if I were better it would have been faster to just code it. It took a lot of English to describe the shape - quite possibly more than it would have taken to just write in openscad. Saying "a cube 3cm wide by 5cm high by 2cm deep" vs cube([5, 3, 2]) ... and as you say, the hard part is before the openscad anyway.
OpenSCAD has a very steep learning curve. The big trick is not to think sequentially but to design the part 'whole'. That requires a mental switch. Instead of building something and then adding a chamfered edge (which is possible, but really tricky if the object is complex enough) you build it out of primitives that you've already chamfered (or beveled). A strategic 'hull' here and there to close the gaps helps a lot.
Another very useful trick is to think in terms of vertices of your object rather than the primitives creates by those vertices. You then put hulls over the vertices and if you use little spheres for the vertices the edges take care of themselves.
This is just about edges and chamfers, but the same kind of thinking applies to most of OpenSCAD. If I compare how productive I am with OpenSCAD vs using a traditional step-by-step UI driven cad tool it is incomparable. It's like exploratory programming, but for physical objects.
