What Doug is saying definitely rings true. A consistent effect of using a Contra drive is increased rudder sensitivity. This is something that I believe I mentioned way back at the start of this thread. What I found was that I was increasing my rudder exponential up to 85% plus in order to soften the rudder around neutral. Also, when I released the rudder, I had to release it slowly or the tail of the plane would swing past center before settling back in line.

What we have found is that increasing the width of the rudder trailing edge dampens these effects, and pulls the tail of the plane back into line. It's kinda like putting a tail on a kite. What I did with my Integral is put two 1/2" triangular strips on the trailing edge of the rudder. This resulted in a softening of rudder sensitivity, and a "dampening" of any yaw oscillation when I released the rudder. This made the rudder much more precise around neutral. Now I can input very subtle rudder inputs, which are very difficult to see from the ground because there's no oscillation. When I fly I'm constantly working the rudder, but the plane still looks like it's tracking straight as an arrow.

The end result is a plane that is an absolute dream to fly because its trim doesn't change with airspeed. It carves like a knife, and tracks like an arrow across the top of Humpty Bumps, and at the end of long verticals. One very beneficial effect is the way it tracks on a vertical line. It can put vertical point rolls on a string, and then continue on a perfectly straight track after the rolls. Also, these same effects make it much easier to do perfect stall turns, because the wings don't twist out of plane as the plane pivots.