I am a reseller of Bricscad because I think Bricsys is the leading developer in the ITC.
Zwcad looks good, very close to AutoCAD, but I think Bricscad is better at customization, VLisp, VBA, .NET and BRX.
Rhino + Bricscad is a good combination.
It's a good alternative too. Our borelog generator works for BricsCAD. This software generates a borelog with soil hatches, levels and texts, based on a plain txt file. So, if you have customers that do soil investigations... Pity Bricsys doesn't want to put this on there addon software list, just because we distribute ZwCAD in The Netherlands. They start behaving arrogant like another famous big CAD company....