Not being familiar with the sting ray this post may be completely useless to you…

One disadvantage to the self tacking jib are that if you need to back the jib to get around in a tack you must hold the jib on the old side or it will just switch sides. This is solved by boats with daggerboards and centerboards that tack much like monohulls. Unlike long asymmetrical hulled boats, which may need the back in a chop.

Another disadvantage to the self tacking jib is the jib cannot overlap past the mast, because the track must be in front of the mast. Many catamaran jib sails over lap and must be modified or a new sail must be created.

As far as furling jib. If your jib has battens you must either have a hollow leach sail built with no battens or you must angle your battens parallel to the forestay.

I just outlined some concerns, but they are both awesome features that I would want.