It seems to me that Richard said in his original post summat like: "if your tube is in the water at speed, you will have very poor high speed handling"
Which is pretty true.
The Argument, sorry, discussion, seems to have been swung around to another angle.
I agree, if at low speed, having ya stableizers on might help with roll stability, but once you're travelling quickly (original statement), a combination of the dynamics of the hull design (a good one that is) and a good driver, who anticipates and corrects for the roll brought on by a beam, or 3/4 sea is fine.
Dragging ya fenders about at speed aint good, they're too bouncy.
A good, if rather extreme example is how easily some of the race ribs with bigger toobs have barrel rolled in a straight line, bouncing from toob to toob.