While I can't speak for BRL-CAD my experience with FreeCad which uses OpenCascade has been mixed. The chamfer/fillet tool there is just broken. If you use that and change some dimension it is likely to randomly crash. So, overall my experience has been ranging from rock solid to total trash depending on which features you use and what kind of models you create with it. The key question is "what do the developers use it for?" which should give you a hint for what kind of problem it is made.