Thanks for updates ;)
I used it a lot, it is a modeler and very precise but it works with the coordinates and you can not do organic shapes flowing like sweep or loft, does not work with surfaces and rendering is outdated. Instead of BRL-CAD I recommend Blender!
A very, very klunky interface. E.g. to run brl-cad on Ubuntu, you need to run mged from the command line. The process of changing attributes is also very tedious. This would have been a great package in the 1980's.