Alternatives Comparison

1. CAD interface

BricsCAD interface has some unique features  which requires some efforts to learn.  For example, the options dialog box is replaced by a Settings panel.

2. Lisp/Macro support

BricsCAD supports Lisp code (.lsp) and VBA (.dvb) directly from AutoCAD

ZWCAD only supports Lisp code (.lsp) directly from AutoCAD.

3. Forums

AutoCAD has a 23-year super forum and AUTODESK has 101 more forums for other categories.

BricsCAD has an acitve Forum while ZWCAD NOT

More information  

In this document, ZWCAD mention about a converter for AutoCAD .vlx, .fas file.  However, I haven't had a chance to touch that.