A vang is lighter, doesn't upset the mainsail, gives mrsdrlee something to grab on light airs gybes, and we understand how to work it.
I liked the gnav on the 29er we sailed, and I think they are a good idea. Just an innovation too far this time.
All good points, fair enough but surely if you make the gnav out of cabon fiber it will be lighter, because there will be less string and blocks.
A gnav like on the 29er is a very good idea for a one-design because it lets them replace loads of expensave blocks with a simple aluminium plate acting as a lever
most cherubs and 14's seem to have gone for the fixed point on mast, slide along the boom type, this is probably because it is simpler to construct than getting all the dimentions of the leaver exactly right.
the problem with building out of carbon is that you nead several bearings, which act as point loads and they need to move. You need to bond on some sort of bearing surface for the pivot while keeping the whole thing strong and small. which is tricky.
In adition when you fall on a string under load it is normally OK a strut on the otherhand will quickly become two struts.
I think Aqua(which had a kicker) would have benifited from the gnav more than Primal(which has a gnav) becuase of the shroud positions and the need to go infront of the mast in light winds on Primal.