My biggest gripe with SolveSpace won't let you write code, everything is done in the UI which is very limiting and a big turn-off, especially given what the underlying geometry engine is capable of.

On the other hand, OpenSCAD doesn't have a constraint solver (you can't easily say something like "compute the intersection of these two circles and project the resulting point on this surface and extrude a cylinder from that point along the normal of that surface"), whereas SolveSpace does, and it's a very powerful way to model things.

OpenSCAD is also very annoying in the sense that it doesn't allow you to "probe" your model to construct it further: it has exactly zero self-introspection features. To give a simple example, it's almost impossible to compute the bounding box of a model or its barycenter, which is very limiting.

Otherwise it’s a bit less flexible — e.g. it’s harder to do value constraints (e.g get dimensions from a spreadsheet); and it isn’t compatible with scripting yet; you can’t just point-click-chamfer your parts; you need to do metric holes and indents for bolt heads manually; etc, etc

But what is available works almost without any problems (except for 3D constraints and occasional problems with difference operations on curved surfaces) — and is soo fun to use.