I have now built a simple model  of my lug rig with adjustable CE, I am very impressed with this rig I think it may well have some real potential. It offers a very clean sail, low CE and steering. Only suitable for small proas like my minimal proa though. 
For discussion see  http://proafile.com/forums/viewthread/244/

for some video see http://www.youtube.com/watch?v=JyE0FsI_GAQ