From my experience it's 100% compatible with the DWG format.
It has both the Overkill and bpoly commands. (I don't have extensive experience using these in it BricsCAD but from what I see it appears to work very similar).
For the average CAD user I would say AutoCAD and BricsCAD are fairly equal.
I use AutoCADMAP which has tools that the Base AutoCAD doesn't... and in my case MAP is slightly superior to both AutoCAD and BricsCAD for what I need.
I'm not sure what Import/Export features the Base AutoCAD has. I'm guessing it basic compared to AutoCADMAP.
Example for shape files BricsCAD import/exporting is very basic... however you can purchase plugins that can fill that gap.
BC imports(dxf,dwg,skp,wmf,emf,...,dae,dgn,obj,3md), Exports(fbx,stl,dwg,dxf,3dm,svg,dgn....) and a few others
GC GISImport(shp), GISExport(shp)
Attach: (dwg,pdf,image,point cloud)
AutoCAD Reliability : AutoCAD has DWG ,BAK, $ac (files). Including auto save scheduling, file Audit, file recovery. This should tell you something how reliable AutoCAD is. Very often the only thing that saves us is daily backups. I been using AutoCAD since version 11 and reliability of files is not something AutoCAD has going for it... but you learn to backup, backup and backup.
They have a 30day trial... install and give a shot:
Most commands are the same, some tools may have a different name so you may need to search the web, check help or check in the BC forum to figure it out.
https://www.bricsys.com/bricscad-download