On Mon, 13 Oct 2003 07:07:18 GMT, "Jeff Richards"
wrote:

The mainsail will have no battens, so it will not hold its shape as well=
as
a conventional main, and the leach will be concave, reducing the area.
Also, it will probably be loose-footed, and this further affects the =
shape,
regardless of how tight the foot is pulled.

Vertical battens are sometimes used with in-mast furling systems. IMHO
performance is probably diminished a little but not that most cruising
types would notice. A cunningham would probably not be used.