I have also been using DesignCad for years and find it very powerful yet easy to use once you are familiar with it. You can set up custom keybpard shortcuts for your most often-used commands.
You can save some steps by using layers to separate the working lines from dimensions, text, and construction lines. Then just select the layer (or any combination of entities), and choose "save selection only" when exporting the dxf file. That way only the lines you need make it to PartWorks.