I remember having a look at sailcut a few years go, was not into sailing back then. Anyone wanting to get into CAD should check out Rhino3d. By far the most precise, advanced and precise modeller out there that can be used with limited knowledge of CAD. I would say Sailcut+Rhino is a good start.
Marcus - could you send me the sail design you are talking about - first for study and will find use on the box rule drawing also.

www.rhino3d.com