Originally Posted by sailingdog
A full battened sail has some advantages over a un-battened sail. First, the sail will often be easier to flake and furl. It will flog less. It will often have better shape. It will often have more roach and more power as a result.
Full batton sails are becomming very popular for racers, but often only the top batton is a full batton. In addition to the advantages SD pointed out, the pocket for the full batton won't have an end to wear (near the luff).
However, you need to do more than have any full batton, you need to have a good quality batton to get the advantage. Good battons these days tend to be light and tapered and are often made from hi tech materials. Racing battons can be carbon fiber, hollow, and very expensive. There are companies that make nothing but battons.
Is this for crusing or racing? If you're crusing around, and the price difference is great, you may not want to bother. Do you have a sailmaker you work with? If so, get his or her opinion.