The elevator on mine would wobble because of the linkage. It would allow the left and right to move. I used some stiffer 4-40 wire and carbon rods and it went away. If you use stock linkage you can grab one of the surfaces with the servo engergized and move it up and down due to flex in the Y shaped control rod. The horizontal stab itself seems to be plenty strong. I bet the one you saw used the stock linkage which is none too great.