Lack of support for other operating systems, ZWCAD only support Windows systems.
For the 2011 version, ZWCAD do not support Polysolid, and other 3D tools. Do not support Presspull command to create solid from any closed objects, faces or regions.
Do not support Extract Edges, which can gain the solid’s 3D profile.
And it depends on what you're working on, you feel the lack of lighting and photorealistic reproduction effects. Review collected by and hosted on G2.com.