^^^^ I find i use the stopper a whole lot. The throw is sooo huge. I think thats because they wanted a lot of depower. But as I have found, once you depower it that much (to where the stopper is at the top) my 12m will barely turn, and the wing tips "squeeze" in. Thats in the 18-25mph wind range. Thats why I just picked up a 2008 9m session.
The 16m and 6m combo would be a way dramatic quiver. It would seem that you would need to either depower the 16 a whole lot. Or work your 6m a ton.
I prefer a 12m and 9m. With a lightwind board and a smaller board.