Alltrikes

Gibbo Gear is coming out with a new wing, a 15 meter double surface, check out their website http://www.gibbogear.com/

In the desciption it says "100% double surface increases top end speed and lowers the stall speed....Not sewing the under surface to the top surface allows the two surfaces to shift independently of each other during flight improving handling. Another cool feature of the detached under surface is you can pre-flight your entire airframe!"

What is difference between a regular double surface wing (which as I understand typically are 80 percent double surface) vs this wing, which is 100 percent double surface.

The other question is a 100 percent double surface wing would be much more cleaner and faster than a 80% double surface wing, how does that help lower the stall speed? If anything I would think that it would increase Stall speed.

Am I right in my thinking?