I have been using the Pacific Action 1.1 meter sail on my Valley Aquanaut (skeg w/o rudder) for several months and have been very pleased with design and functionality. I'm a lifelong sailor, and always frustrated in a kayak when I cannot use the wind.
The most interesting feature of this design of "V" sail is the sheet attached to the midline of the split via mast on either side. This does allow adjustable sail trim, and in light air does allow for relatively safe and fast reaching. I would never have thought possible the ability to reach in a kayak with limited or no feeling of capsizing. The boat appears to track well at this point-of-sail, and does not necessarily require the skeg down.
Installation does require drilling the holes in your boat, including two small brackets to hold the base of the mast, and in my case I placed to the cam cleats just in front of the cockpit which are very functional, and are useful for other applications than the sail sheet. A very nice feature of the rig is the bungee tensioning at the bow, allowing both masts and sail lowered and placed under deck bungees within seconds. The length of the mast fits in front of my cockpit with inches to spare, and for this reason I would think many conventional kayaks would probably not desire a greater sail area the 1.1 meter.
The only downside I have found in the rig is related to the tensioning device which connects the mast to a "deck roller" which allows the sail to be taken down and put up rapidly. This device has been somewhat difficult to tension, which allows the sail to become more slack than desired when sailing downwind.
This sailing system was designed in New Zealand, and was clearly set up by good Kiwi sailors. I would recommend it for anyone looking to add the dimension of sailing to their kayak, without interfering or altering the classic nature or structure of their boat.