Originally Posted by sailingdog
That said... they can often give better performance than un-battened sails. They tend to flog less and are often easier to reef and flake, since the battens tend to keep the sail aligned. They allow you to carry more sail area than you could with out them.
SD, it's true that battens require extra cost/work, but unless the mainsail in question has an extremely high aspect ratio (not likely to be found on a cruising cutter), an un-battened conventional-variety mainsail will never be able to hold an aerofoil shape properly.
Adding roach will only make it worse because there is nothing to support the leech. Heck, I've even see people battened jibs!
By not having the stiffness aft that the battens provide, maximum draft will be a lot further aft than normal and this could induce weather helm.