I used to use M-Color and I loved it. The AutoCAD plug-in software works by creating closed polylines and it automatically fills them by layer. Using pre-formatted templates for prototype buildings and a standardized palette, I was able to crank out three different site plans in a day with this as coloring is pretty much instantaneous. All you do is plot to M-color as you would a PDF. The images (I usually used PDF) are also very small, making it very easy to e-mail. I tried to get my last employer to bite on it, as it would have at least doubled productivity over hand drawing and coloring in archaic Corel and later photoshop. And because you can use a standardized palette, all of your output is consistent.
http://www.m-color.com/