Back in 1999, FIT, Inc re-released Cadvance v6.5 as a free download from the Cadvance web page. In nearly five years, some 30,000 copies have been downloaded. (The original 1995 price was US$1,950.)
Is this "old" software for you? It is, afterall, a CAD software system written for Windows 3.1, but runs on Windows 95/98 and NT. When it's a free download, you can check it out for yourself. Often, I find, the user interface matters more than the feature set.
Cadvance has a long history, just predating AutoCAD. It was launched in 1982 as CADplan by P-CAD of San Jose CA USA. The plotter manufacturer CalComp bought it, then later sold it to ISICAD -- which is when I became aware of it. I recall Yoav Etiel coming by my office (1993) to show me this CAD package that ran on Windows -- unusual at the time.
Being one of the first CAD packages ported to Windows, however, didn't make Cadvance a winner. In 1995, Furukawa Information Technology of Anahim took over the the business. Today, the current version of Cadvance is 2002 with Service Pack 6.
As for CalComp (also located in Anaheim), it was bought by Lougheed, but later went out of business and was subsequently purchased by GTCO.