Coulter_Dean,
Just so you know, I don't fly my Stickits in competition. But for the past ten years, I've been actively sport flying a couple of Stickit IV planes. It's sport flying......but usually wild and crazy sport flying at extremely low altitudes (see avatar), and in situations where if the engine stumbles, my Stickit usually crashes. Therefore my particular setups might not be competitive on a national level, but I've never seen another plane yet that could out fly it. And I'm also my club's test pilot so I get to fly a lot of other planes to compare them to my Stickit IV. So far, the ONLY other planes that can begin to compare with my Stickit IV have been similar wing and boom types. And now that my disclaimer is out of the way, if I were to build another Stickit IV, I would do the following:

Add diagonal cross braces to the aileron structure. They added a lot of strength with very little weight penalty.

Trim off the tips of the ailerons to angle back about 30 to 45 degrees. I can't even begin to count the number of times I've broken the tips of the ailerons while playing around at ground level. The wingtip skids didn't prevent this damage either.

Leave off the wing tip skid wires. I took mine off later on, and I haven't missed them at all. (during ground level playing around, the skids usually caused more damage than they prevented.)

Use at least a 4-40 pushrod on the ailerons. Better yet, make them pull-pull.

Seal your aileron hinge gaps! If you don't, you are almost guaranteed to experience aileron flutter. Plus the loop tracking suffers without the sealed gaps.

Change the rudder pushrod to a pull-pull cable. It's simple, lightweight, and allows you to get LOTS of rudder throw. I would definitely recommend this.

Change the elevator pushrod from a nyrod type to a 1/16"
solid music wire pushrod, with nylon guide tubes placed about every 6". Be sure to position your guide tubes so the wire runs absolutely as straight as possible from the servo to the elevator horn. A bow or a bend in the pushrod wire will allow it to flex.....which could result in a flutter. Note: If it weren't for the bottom elevator control horn dragging on the ground, I'd use a pull-pull for the elevator too.

Leave off the tail skid wire. My tailskid wires always broke off after less than 30 flights, so I finally stopped replacing it....and I haven't missed it either. (but it's a grass field)

Modify the bottom of the rudder to allow the elevator to deflect at least 60 degrees.

Make the elevator at least 50% of the horizontal tail area. This will help to eliminate the flapperon deflection overpowering the elevator control in some cases.

Eliminate the removable stud that the tail surfaces mount to. I have mine mounted with a 6x32 bolt, and it still tends to wallow out the bolt hole, which cause the tail section to tilt to one side or the other. I can't imagine a little 2x56 screw lasting more than a few aggressive flights! Get your tail section squared up, then glue the stud in solid. Or just eliminate the stud entirely.

Mount the servos with the arms above the hatch, like on the Stickit V version. This will especially help to eliminate the pushrod interference problem with the center rib on the elevator servo at extreme throws.

Reinforce the outer rib bay by adding a full sheer web in that section only. Also fiberglass the inside of the leading edge sheeting of the just the outer rib bay. This area takes a REAL beating when you get to playing too hard!

Use FAST servos that have adequate torque to do the job, then use a 5 cell pack to make your servos even faster. Most servos sold as "high torque" are way too slow for a Stickit with +/- 60 degrees of throw. The result is that the control surface is always trying to catch up with the stick commands...which makes it harder to fly.

And finally, keep in mind that these are my opinions......and I could be wrong! :stupid: