I don't think that "duped" is fair, though - IMSI Design has been very clear that these are two different code bases and that files are not transferable.
True, duped is probably a bit harsh, but IMSI acquired that software firm quite a few years ago. They should have merged the file structures by now. Several forward looking utility software firms have come to the realization that their user base uses both MACs and PC at the same time, and sell their software so that it can be installed on two computers at the same time, one laptop and one desktop. IMSI has not seen fit to do so.
I don't see why .dxf or .dwg files wouldn't provide some means of transferring data between the two programs, however.
Neither do I. Too bad it doesn't work as well as it should. I've yet to take a complex drawing file from windows and had it transfer all of the data to the MAC via a *.dxf file. Moreover, I have not been able to save a MAC file into a *.dxf format. The only thing that gets written to the disk is the file name, but the fill is empty, i.e., zero bytes. (The DWG format doesn't work in either direction.)
Duped? Perhaps not, but disappointed? Yes. Greatly disappointed.