Originally Posted by davereap
I am not sure on the aerodynamics, but isn't sweep back often equated to dihedral.. so many degrees sweep = so much effective dihedral... ... ..And when you use the rudder to hold the nose in Knife edge it will roll the model rather than just yaw it..
Oh, I forgot about that!
You're exactly right, sweep will couple roll into the yaw.
It makes the airplane feel very well behaved for the sort of sporty cruising around and punching holes in the sky a lot of us tend to do (which is why so many of us like it), but I can see that making knife edge flight really tough.