Wayne,

Personally I think the item volume has always been overrated when talking about the F16. It's clear the Viper has more volume and higher bows then any other F16 design, but I'm convinced this added volume will not contribute to the performance of the Viper compared to the Blade/Falcon.
I think one of the major improvements of the Falcon compared to the Blade is that there is less volume at the transom and that it is higher out of the water.

What I mean is that we do not have any pitch pole problems with our Blade now, but that if we sit/trap out far enough aft not to pitch pole the transom is in the water causing quite some drag. Even upwind (in heavy seas/winds) this sometimes happens. The new design seemes to cope with that which should be a speed improvement up and downwind.

But this is ofcourse only my personal opinion.

Gill